Memory and its Types

     What is Computer Memory? 

   Ans: A Computer memory is just like a human brain. A human Brain store data and information also like a  Computer memory store data and information. It is a physical device capable of storing information temporarily or permanently. In other words, it is called a storage space or like a storage container where we are store data and information. 
  There are two types of Computer Memory: Primary Memory and Secondary Memory
    1. Primary Memory: Primary memory is a volatile memory. It is stored only those data and instructions when a Computer is currently on. It is a small storage capacity memory and data is lost when the computer power is switched off. 
     Primary memory primarily three types:
     i. Cache Memory: Cache memory is a very high-speed memory. It acts as a buffer between the main memory and the CPU.

1. It is the fastest memory of the computer system.
2. It is inbuilt in the processor.
3. It is a supplementary of RAM.
4. It is also called CPU memory

ii. Random Access Memory(RAM)

1. Random Access Memory.
2.  It is the Main Memory.
3. Temporary Memory.
4. Volatile Memory.
5. It is display Memory
6. It is sometimes called physical memory.

Types of RAMs: DRAM (Dynamic RAM) and SRAM (static RAM)

DRAM:

1. DRAM requires periodic refreshment.
2. It is slower and dynamic in nature.
3. More power consumes and cheaper.

SRAM:

1. SRAM retains data bits without periodic refreshment.
2. It is slower and dynamic in nature.
3. More periodic refreshment.

iii. Read Only Memory(ROM):

1. Read-Only Memory.
2. It is called BIOS Chip.
3. It is a permanent memory.
4. Non Volatile Memory.
5. It is also called Firmware.
6. It performs the Booting Process and POST process.

Types of ROM:- PROM, EPROM, EEPROM.

PROM:-Programmable Read Only Memory.

EPROM:-Erasable Programmable Read Only Memory

EEPROM:- Electronically Erasable Programmable Read Only Memory.

2. Secondary Memory:

Secondary Memory:-It is where programs and data kept on a long-term basis. It is a large volume storage device. It is also called permanent memory and Auxiliary memory.

Example: Hard Disk Drive, CD, DVD, etc.

HDD:- Hard Disk Drive –(40GB, 80GB, 500GB,1TB)

FDD: Floppy Disk(1.44MB)

CD:- Compact Disk(700MB)

DVD:- Digital video Disk Digital Versatile Disk (4.7GB)

SD Card :- Secure Digital (1GB, 2GB, 4GB, 8GB,16GB, 32GB, 64GB)

PD:-Pen Drive (1GB, 2GB, 4GB,16GB, 64GB)

On the Basis of storing Technique, memory is three types:

1. Magnetic Memory :(Use tiny magnetic spots.)It is two types:

a. Magnetic Tape (Analog Data –Reel used in camera and Cassettes.) and

b. Magnetic Disk (Digital Data- Floppy Disk, Hard Disk)

2. Optical Memory: (Tiny hole pits on reflective metal layer coated in plastic). Example:- CD, DVD

3. Semi-Conductor Memory: (Uses transistor and registers for storage). Example: ROM, PROM, and RAM.

Another Kind of Memory is :

Flash Memory: Flash memory is a kind of memory that retains data in the absence of power supply.

Example:- Semiconductor memory, PD, SD Card, etc.

Unit of Memory :

Bit- Binary digit (0,1)

4 Bit                                    =       1 Nibble

8 Bit                                    =        1 Byte

1024 Byte                           =        1 Kilo Byte

1024 KB                             =        1 Mega Byte

1024 MB                             =        1 Giga Byte

1024 GB                             =        1 Tara Byte

1024 TB                              =        1 Peta Byte

1024 PB                              =        1 Exa Byte

1024 EB                              =        1 Zeta Byte

1024 ZB                              =        1 Yotta Byte

1024 YB                              =        1 Bronto Byte

1024 Bronto Byte               =        1 Geop Byte

1024 Geop Byte                 =        1 Sagan Byte

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Debit and Credit Rules, Cash and Credit Transaction Finding Rules.

Golden Rules of Debit and Credit

Personal Account:

             Debit : The Receiver

             Credit : The Giver

Real Account:

               Debit : What comes in

             Credit : What goes out

Nominal Account:

               Debit : All Expenses and Losses

             Credit : All Income and Gains

Cash and Credit Transactions Finding Rules:

Sometimes transactions are worded in such a way that it becomes difficult to decide whether they are cash or credit transactions. The following rules will make the position clear:1. A transaction is regard as a cash transaction if:2. A transaction is regarded as a credit transaction if:(a) The word "cash" is mentioned in the transaction. For example Bought goods for cash Rs. 5000 from A.(b) The name of the seller or buyer is not mentioned in the transaction. For example, Bought goods Rs. 5000.(a). The words "on credit" or "on account" are mentioned in the transaction. For example, Bought goods worth Rs. 5000 on credit.(b). The name of the seller or buyer is mentioned in the transaction and the word "Cash" is not mentioned. For example, Bought goods from A worth Rs. 5000.Every business transaction brings a double change in the financial position of the business. It brings a change in the assets, liabilities, owner's equity, expenses or revenues of a business.

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Fundamental of Computer Theories

1.What is a computer?

Ans: A computer is a High Speed Digital electronic device that operates under the control of instructions  and it has the ability to store, retrieve, and process data. It is a collection of two components Hardware and Software.

Classification of Computer

Classification based on Purpose:

1. General Purpose Computer

2. Special Purpose Computer

Classification based on Type:

1. Analog Computer :

Analog Computers are used mostly in Medical Sciences. This very kind of Computers work on Continuous data values, for eg. if you have to calculate the pressure or something similar then kind of technology having will be useful.

2. Digital Computer :

Digital Computers are the most commonly used computer on a digital technique which is widely used and preferred now-a-days. This kind of computers uses micro processor technology which is quite digital and able to calculate and execute million of instruction within a second. This also comes under kind of categories as we can see downwards..

3. Hybrid Computer :

The kind of computer comes with both characteristics (digital and analog) are called hybrid. This is used there where it needs to calculate both the digital and analog data for e.g. In Hospitals.

Classification based on Size:

1. Micro Computer (Personal Computer) : 

The processor is very small so that called Micro processor and device is called Micro Computer. Micro Computer is single user device example: Desktop, Laptom, Palmtop, Notebook, PDA, etc.

2. Mini computer :

The processor of Mini Computer is small but larger than Micro processor. Mini Computer is multi user device generally used in designing company for commercial use.

3. Main frame Computer :

It has larger processor and multiuser device. Number of users is more than Mini Computer. This is multiuser and multitasking device mostly used in Metrology.

4. Super Computer:

The processor is biggest than other Computer and processing capacity is highest than other devices. It is multi user fastest calculating device, generally used in nuclear science for calculation purpose. CRAY-I is the first Super Computer. India's First Super Computer is PARAM-10000

4.Some Advantages of a Computer :      

ANS :-1. Very high speeds

           2. Large storage and retrieval Capacity

           3. Accuracy in calculation         

           4. Versatility(Multiple Task/ Multitasking/ Multiple Work) 

           5. Diligency

5. Some Disadvantages of a Computer :

ANS :-1. Cannot think                

           2. Cannot learn by experience 

        3.Cannot take independent decision.Requires human instruction to take a decision.

6. What is Software ?

ANS : Software is the series of instructions that tells the hardware how to perform tasks. Without software, Hardware is useless. Hardware needs the instructions provided by Software to start work.

7. Software two type :

ANS : 1. System Software

            2. Application Software

8. What is Hardware ?

ANS : The electric electronic and mechanical equipment that makes up a computer is called hardware. Hardware is any part of a computer you can touch and feel any peripheral equipment such as Keyboard, Printer, Monitor, Speakers and Mouse devices.

9. What is input device?

Ans: Data entered into a Computer is called input devices.

Some examples of input devices are :   

1.Keyboard 2.Mouse 3. Joysticks  4. Touch Screen 5. Digital Camera 7.

Video conferencing 8.Voice input 9. Audio input.

10. What is output device?

Ans: Computer is fed with a lot of data to be processed and organised. The data that has been processed in to a useful form is called output devices.

Some example of output  devices are :

1. Monitor 2. Video Card 3. Printers 4. Speakers.

11. Mention the name of four early computer .

ANS:-1.Mark I 2.ENSIC  -Electronic Numeric Integrator and Calculator 3.EDVAC –Electronic Discrete Variable Automatic Compurer  4.UNIVAC –Universal Automatic Computer.

12. Any  computer system can broadly  classified in terms of  four component dimensions:

*Hardware

*Operating system

*Application programs (like ms word, Games,Calculator)

*User (people who work on the computer)

13. Generation of Computer

First Generation

First generation computers,starting with the UNIVAC I in 1951, used vacuum tubes and their memories were made of thin tubes of liquid mercury and magnetic drums.

Second Generation

Second general systems in the late 1950 s replaced tubes with transistors and used magnetic cores for memories (IBM 1401,Honeywell 800).size  was reduced and reliability was significantly improved…….

Third Generation

Third generation computers, beginning in the mid 1960s, used the first integrated circuits(IBM 360,CDC 6400) and the first operating systems.online systems were widely developed,although   most processing was still batch oriented, using punched cards and magnetic tapes.

Four Generation

The fourth generation which start in the mid 1970s, brought us computers made entirely of     chips.It spawned the microprocessor and personal computer.It introduced distributed processing and office automation.For the first  time,query languages,report writers and spreadsheets put large number of people  in touch  with the computer.

Fifth Generation

Fifth generation computer are expected to combine very large  scale integration (VLSI)with sophistication approaches to computing, including artificial intelligence and true distributed processing.

Windows XP

Microsoft windows XP is an operating system program that controls the overall activity and ensures that all parts of your computer work together smoothly and efficiently of your computer.

Basic components of Windows

1. My Computer:The my computer icon,on a windows desktop includes the disk drives and system folders,which the control panels and dial-up networking.

2. My  Documents:It provides a convenient place to store your documents.

3. Recycle Bin:In windows,an icon of a waste can used for deleting files .It stores deleted files and allows you to recover them later.

4. My network place:It allows you to view the folders and files available on your network.

5. Desktop:It is a background area of your screen.
                                                   

6. Start Button:It provides quick access to programs and files.

7. Quick Launch toolbar:Provides quick access to commonly used features.

8. Clock:Displays the current time.

10. Windows:A Windows is a rectangular area on screen surrounded by a window frame with a title at the top.When you launch a windows application.It is displayed in its own window.Each subsequent application is displayed in another.

11. Scrollbar: A horizontal or vertical scrollbar that contains a box  that looks like on elevator in a shaft.The bar is clicked to scroll the screen in the corresponding displayed in another.

12. Title bar: Displays the name of an open windows.

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Client Server Architecture of Internet.

Client Server Architecture of Internet.

The concept of client-server architecture is important in the context of Internet because Internet works based on it. It is an application that is composed of a server program and a client program. These two programs

communicate through networks. The server program is often called server, a server is a piece of software, not some hardware. The computer on which the server program is executed is called a server computer.

The client program is also called client. 

The server program has the following characteristics:

1. It is a program designed for providing a particular service.
2. When the server computer boots up, the server program is usually invoked automatically, the service is always available.
3. It waits passively for clients requests Upon receiving one request, it performs the necessary computation and returns the result to the client.
4. In many applications, a server is designed such that it can serve multiple clients simultaneously.

The client program has the following characteristics:

1. It is an application program executed by an end user on a local computer.

1. When it needs a service, it sends a request to the server programs, and then waits for the response from the server program.

1. It can request multiple services when it is necessary.

Internet Protocol:

The Internet Protocol is the method use a transport protocol to send and receive data from one computer to another. It is the set of communications protocols that implement the protocol stack on which the Internet runs.

A protocol stack is a complete set of protocol layers that work together to provide networking capabilities.It most commonly refers a  set of rules that enables computers to connect and transmit data to one another; this is also called a communications protocol. The Internet protocol suite is sometimes called the TCP/IP protocol suite, which refers to the two most important protocols in it: the transmission control protocol(TCP) and Internet Protocol(IP).

Some important Protocol are:

Simple Mail Transfer Protocol:

It is the protocol used for electronic mail (E-mail) transmission across the internet Protocol(IP) networks. SMTP uses TCP port 25. SMTP is used by most of the email systems to send messages from one server to another over the Internet. In simple words we cans say that SMTP is mainly used to send messages or mails from a mail client to a mail server SMTP  actually performs two transfers:

1. from the senders computer to the sender's SMTP server and

1. from the sender's SMTP server to the receiver's SMTP server.

POP3: 

The Post Office Protocol (POP) is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection. The "3" means it is the third revision of the standard; POP1 and POP2 were made obsolete by POP3. A POP3 mail server receives e-mails and filters them into the appropriate user folders. When a user connects to the mail server to retrieve his mail, the messages are downloaded from mail  server to the user's hard disk.

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Definition:- Source Document & Vouchers and Features, Advantages, Categories.

Definition:- 

            A source document is a written document which becomes the basis for recording a transaction in the books of accounts. Such a document is the proof of happening of a transaction. It shows the nature of the transaction, the amount involved in the transaction, the date and the name of the parties involved. Such written documents are called vouchers.

        Vouchers include receipts, bills, cash memos, invoices, wages bills, salaries bills, travelling allowance bills, counter foils of cheques, registration deeds, customers agreements and any other form of written proof that shows that a transaction has take place. Such documents are verifiable documents on the basis of which transactions are recorded in the books of accounts.

According to J.R. Baltiboi: 

"A voucher may be defined as documentary evidence in support of an entry appearing in the books of accounts".

According to Rolald A. Irish: 

"A voucher may be a receipt, an invoice, an agreement, written requisition slip or in short any suitable written evidence which confirms a written transaction."

Features of a voucher:

From the above definitions, it appears that a voucher has the following features:

1. A voucher is a written document.

2. It describes the transaction in details;

3. It is a documentary evidence of the happening of a transaction;

4. It supports an entry made in the books of account.

5. It substantiates the accuracy of an entry made in the books of account.

Importance/Advantages:

       A source document has the following advantages.

1. Documentary evidence : 

       A source document acts as an evidence in support of a business transaction. It authenticates that a transaction has really taken place.

2. Basis of recording internal transactions:

      Source documents are prepared and used for the purpose of recording of internal transaction such as depreciation of fixed assets, issue of materials from stores to factory. etc.

3. Origin of transaction:

    The origin of a transaction can be traced to a source document and thus it removes any doubt regarding the occurrence of a transaction.

4. Legal proof:

      It can be used in the Court of law as a legal proof about the genuineness of a transaction.

5. Basis of audit, tax assessment and insurance claim etc.

    Source documents are used as basis of vouching, calculation of tax and assessment of insurance claim.etc.

Categories of Vouchers: 

The following are the categories of Vouchers on the basis of the parties who prepare them:

1. External Supporting Vouchers:   

     External Supporting Vouchers are those vouchers which are prepared by the parties other than the parties who receive them. Example of such vouchers are Purchase Invoices received from the parties who supply the goods. Cash Memos obtained from the seller from whom goods are purchased in cash. Cash Payment Receipts for payment of expenses. Debit Note received from the supplier for return of goods by the business; Credit Note received form the customers for goods returned by them.

2. Internal Supporting Vouchers:

     Internal Supporting Vouchers are those vouchers which are prepared by the business organisation. Different source documents or vouchers necessary for recording transactions in different books are given below:

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What is Transaction ? Classification of Transactions:

What is Transaction?

A Transaction means an event which changes the financial position of a person or an institution measurable in terms of money. Thus a transaction means any exchange of goods or services or the happening of any loss or gain, measurable in terms of money, bearing documentary evidence and affecting assets, liabilities, capital revenues and expenses.

Definition:

          According to Field house:- "Every financial change which occurs in your business is a transaction."

                According to Noble and Niwonger :- "Any happening which brings change in the pattern of assets or liabilities or proprietorship of a business concern is a financial transaction to it."

Classification of Transactions:

1. Classification on the basis of the mode of payment. Transaction are Three types.

       a. Cash Transactions:- Cash transactions are those transactions where the value of the transaction is paid immediately either in cash or by Cheque. As for example; Hari bought goods for Rs. 500 in cash from Guwahati Store. It is a cash transaction. In a cash transaction , either the word cash will be mentioned in the transaction or the name of the party will be absent from the transaction.

   b. Credit Transaction:- Credit transactions are those transactions where the value of the transaction is paid later on. As for example; Ram purchased furniture valued Rs. 2000 from Furniture House on credit. Here the payment is not made immediately after the purchase of furniture it is to be paid later on. So it is a credit transaction. In such a transaction the words on credit or the name of the party will be mentioned in the  transaction.

    c. Paper transactions:- Paper transactions are those transactions where the value of the transaction is not to be met at all. For example; A loss by fire (uninsured) to the extent of Rs. 10,000 is a paper transaction as the value of the transaction is not to be met. The words "Cash" or "on Credit" will not be used in such transactions.

2. Classification on the basis of the entity involved:Transaction are Two types.

          a. External Transactions:- External  transactions are those transactions which take place between the business entity and another entity or a party outside the business.Example: Sale of goods to a customer.
       b. Internal Transactions:- An Internal transaction is one that takes place within the business entity itself. Example: The depreciation of machinery used in the business.

3. Classification on the basis of exchange:Transaction are Two types.        

      a. Exchange Transaction :-An exchange transaction results in an exchange of value between two or more parties. Examples:- Sale or purchase of good; payment of rent etc. 

     b. Non- Exchange Transaction:- A non-exchange transaction does not result in an exchange of value. Example:- Loss due to fire, flood or theft. depreciation on fixed assets etc.

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Definition: Book Keeping, Accountancy, Accounts and its types.

Definition of Book Keeping:

Book Keeping is the art of recording transactions in terms of money or money's worth systematically in a set of books so that the financial position of an undertaking and its relationship to both its proprietors and outsiders can be readily ascertained at any time.

R.N. Carter defines it as follows, "Book keeping is the science and art of correctly recording in books of accounts all those business transactions that result in the transfer of money or money's  worth". Carter's definition of book keeping contains the following elements:

1. The application of knowledge in certain rules, regulations and theories;

2. Writing up transactions in a set of books.

3. The transactions taken place in money or money's worth i.e financial transactions;

4. Regular and correct recording of transactions.

5. Providing preliminary records for further processing by an accountant.

Summary:

         Book-keeping may be defined as the science and art of identifying and recording accounting transactions having documentary evidence systematically in the proper books of accounts. It is concerned with journal, ledger, cash book and other subsidiary books but not with disclosing or interpreting the results of the business.

Definition of Accountancy:

Accounting is defined by American Institute of Certified Public Accountant (AICPA) “as an art of Recording, Classifying and Summarizing in a    significant   manner and in the terms of money. Transactions & events which are part at least of financial character and interpreting the results thereof” 

What is  Accountancy?

Ans: Accountancy is the practice of recording, classifying, and reporting on business transactions for a business. It provides feedback to management regarding the financial results and status of an organization.

Types of  Accounts?

Personal Accounts :  

The accounts which relate to persons.Personal accounts include the following.

i) Natural Persons : 

 Accounts  which  relate  to  individuals.  For example, Mohan’s A/c,  Shyam’s  A/c etc.

ii)  Artificial  persons :  

Accounts   which  relate to  a group  of  persons or firms or institutions.  For  example,  HMT Ltd., Indian Overseas  Bank, Life Insurance Corporation of India, Cosmopolitan club etc.

iii) Representative Persons: 

Accounts which represent a particular person or group of  persons. For example, outstanding salary account, prepaid insurance account, etc.

Real Accounts:  

 Accounts relating to properties and assets which are owned by the business concern. Real accounts  include  tangible and intangible accounts. For  example, Land,  Building, Goodwill, Purchases, etc.

Tangible Real Accounts:

Tangible real accounts are related to things that can be touched and felt physically. Few examples of tangible Real Accounts are cash, stock, building, machinery, furniture land, etc.

Intangible Real Accounts:

Intangible real accounts are related to things that can't be touched and felt physically. Few examples of such real accounts are trademarks, patents, goodwill, etc.

Nominal Accounts:   

These  accounts  do  not have any existence, form or shape. They relate to  incomes   and   expenses and  gains and losses of a business concern. For example, Salary Account, Dividend Account, etc.

(a) Classify the following items into Personal, Real and Nominal Accounts.

1.Capital 2. Sales 3. Drawings 4. Outstanding salary 5. Cash 6. Rent

7. Interest paid  8. Indian Bank  9. Discount received  10. Building

11. Bank 12. Chandrasekar 13. Murugan Lending Library

14. Advertisement 15. Purchases.

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