The computer is an electronic device that can be instructed to carry out sequences of arithmetic or logical operations automatically. The ability of computers to follow generalized sets of operations known as program enables them to perform an extremely wide range of tasks automatically.
A computer system consists of two major elements which are computer hardware and software.
The computer hardware is a collection of physical parts of a computer system. This includes the monitor, keyboard, mouse etc. Hardware also includes all the parts inside the computer case, such as the hard disk drive, motherboard, video card, and many other parts. Computer hardware is that which you can physically touch.
- The input unit is an external device that is connected to the CPU.
- This unit is used to input data and instructions for solving the problem.
- The control unit is used to sends a signal to this unit for receiving data and instructions from the user, which is communicated to the CPU.
- Examples: Keyboard, Mouse, Joystick, Scanner, Trackball, Light Pen, Touch screen, Touchpad, Bar code reader, Microphone, etc.
- This is used to display the result obtained after execution of a program.
- Whenever the user wants to display output from the computer, the control unit sends a signal to this unit to be ready to accept processed data from memory and display it on screen.
- Examples: Printer, Monitor, Scanner, Plotter, Speaker, Headphones, etc.
CPU(central processing unit):
CPU fetches program instructions from RAM (input), interprets and processes it (execution) and then sends back the computed results so that the relevant components can carry out the instructions.
It is further divided into two components:
- ALU (Arithmetic & Logical Unit).
- CU (Control Unit).
ALU(Arithmatic and logical unit):
- All calculations are carried out in the ALU.
- ALU consists of electronic circuitry which is used to performs the basic arithmetic operations like +, -, *, /.
- It also consists of electronic circuitry that performs logical operations are gives us results in the form of true or false.
- It controls and coordinates that activities of all the units of a computer system.
- It acts as the central nervous system of the computer.
- It controls and times signals to various units to co-ordinate for the specific operation.
- This is a storage device of the computer.
- The memory unit stores the data and instructions given by the user and the result produced after processing the same data.
- There are mainly two types of memory, volatile memory and the other is a non-volatile memory.
- In volatile memory, information is retained as long as power is supplied to the chips if power is offed content is immediately lost. In non-volatile memory, information is retained, even though power is not supplied.
Computer software is a computer program which is a sequence of instructions designed to direct a computer to perform a certain task. Software is an interface between user and computer system. It is mainly responsible for controlling, integrating and managing the hardware components of a computer system and for accomplishing a specific task. Different software’s are used to solve different kind of problems.
- System software
- Application software
System software consists of several programs, which are responsible for controlling, integrating and managing the individual hardware components of a system. The system software is generally prepared by computer manufacturers. These software programs are written in low-level languages, which interact with the hardware at a very basic level. The system software serves as the interface between the hardware and the users. It enables application programs to execute properly. It consists of three basic operations as follows:
- Saving data on disk
- Making a computer to work for us
- Printing a document etc
eg: Operating system
Operating System: An OS is a collection of software that manages computer hardware resources and provides common services for computer programs.
The Operating system is a vital component of the system software in a computer system.
Application programs usually require an Operating System to function.
Application software is specific purpose software which is used by user for performing specific task. It includes set of programs that do real work for users. There are two types of application software.
1. General Purpose Software:
These are designed to perform a general task. Examples are:
Word Processing Software: Enables users to create, edit, format and edit text documents such as letters. Example: Microsoft Word, Open Office etc.
Presentation Software: Those softwares are used for Practice of showing and explaining the contents of a topic to an audience or learner visually. Example: Microsoft PowerPoint, Corel Presentation etc.
Electronic Spreadsheet Software: Enables users to manipulate a table of data usually making numerical and business calculations and projections. Examples: Microsoft Excel, Corel Quattro Pro, Lotus 1-2-3 etc.
DBMS Software: Database management software Enables users to create and maintain a database in which data is organized for ease of use and manipulation. Example: Access, SQL Server, MySQL etc.
Desktop Publishing Software: These are the tool for graphic designers and non-designers to create visual communications for professional or desktop printing as well as for online or on-screen electronic publishing. Example: Quark Express, Adobe Page Maker etc.
Graphics Software: Enables a person to manipulate visual images on a computer system. Example: Adobe Photoshop etc.
Multimedia software: Multimedia software includes a combination of text, audio, still images, animation, video or interactivity content forms.
2. Specific purpose software:
- Inventory Management System and Purchasing System An attempt to balance inventory needs and a requirement to minimize total cost, resulting from obtaining and holding an inventory.
- Payroll Management System Enable organization to encompass every employe of the organization who receives a regular wage or other compensation.
- Hotel Management System
- Reservation System
difference between system software and application software:
|System software||Application software|
|The system software is used for operating computer hardware.||Application software is used by user to perform specific task.|
|System software are installed on the computer when operating system is installed||Application software are installed according to user’s requirements.|
|In general, the user does not interact with system software because it works in the background.||In general, the user interacts with application sofwares.|
|System software can run independently. It provides a platform for running application software.||Application software can’t run independently. They can’t run without the presence of system software.|
|Some examples of system softwares are compiler, assembler, debugger, driver, etc.||Some examples of application softwares are word processor, web browser, media player, etc.|
General software features and recent trends:
Features of a good computer program
- Portability: A program should be supported by many computers. The program should compile and run smoothly on different platforms.
- Maintainability: It is the process of fixing program errors and improving the program. If a program is easy to read and understand, then its maintenance will be easier.
- Efficient: Program is said to be more efficient if it takes less space and easily converted to machine language.
- Reliability: The user’s actual needs will change from time to time, so the program is said to be reliable if it works smoothly in every version.
- Machine Independent: Program should be machine independent. Program written on one system should be able to execute on any other without any changes.
- Cost Effectiveness: Cost-effectiveness is the key to measure program quality. The cost must be measured over the life of the program and must include both cost and human cost of producing these programs.
- Flexible: Program should be written in such a manner that it allows adding new features without changing the existing modules.
- Interoperability: The ability of software to exchange information with the other applications. With the help of these characteristics, the use of information can be made transparent.
- Correctness: Every program should meet all specifications expected by the users.
- Reusability: The software can be called reusable if the users will have the ability to use the software code with some modification for different purposes. More complex software can be developed in a short span of time by reusing the existing software.
- Security: In recent times, security threats have increased over the internet. As a result of which, this factor has become extremely important. There should be a proper measure taken while developing software due to which user’s data can be kept safe from threats.