CLASS IX
COMPUTER APPLICATIONS
Textbook: DINESH Super Simplified Computer Applications BY Dr. Vipan Arora
UNIT – 1
BASICS OF INFORMATION TECHNOLOGY (PART – 2)
INTRODUCTION
Software is a program that enables a computer to
perform a specific task.
It consists of programs to perform specific tasks.
• Software is a set of programs, which is designed to perform a well-defined function. • A program is a sequence of instructions written to solve a particular problem.
There are two types of software −
System Software
Application Software
System software is a type of computer program that is designed to run a computer's hardware and
application programs.
System Software
If we think of the computer system as a layered model, the system software is the interface between the hardware and user applications.
Systems software can be categorized under the following: ❖ Operating system: Harnesses communication between hardware, system programs, and other applications. ❖ Device driver: Enables device communication with the OS and other programs. ❖ Firmware: Enables device control and identification. ❖ Translator: Translates high-level languages to low-level machine codes. ❖ Utility: Ensures the optimum functionality of devices and applications.
Operating System:
➢ It provides common services for computer programs. ➢ An OS acts as a link between the software and the hardware.
The most important tasks performed by the operating system are
1. Memory Management: The OS keeps track of the primary memory and allocates the memory when a process requests it. 2. Processor Management: Allocates the main memory (RAM) to a process and de- allocates it when it is no longer required. 3. File Management: Allocates and de-allocates the resources and decides who gets the resources. 4. Security: Prevents unauthorized access to programs and data using passwords. 5. Error-detecting Aids: Production of dumps, traces, error messages, and other debugging and error-detecting methods.
Popular OSs for computers are:
Windows 10 Mac OS X Ubuntu
Device Drivers
Examples of devices which require drivers: • Mouse • Keyboard • Soundcard • Display card • Network card • Printer
Firmware
It directly manages and controls all activities of any single hardware. Programming Language Translators
These are intermediate programs relied on by software programmers to translate high-level
language source code to machine language
code.
There are 3 different types of translators as follows: Compiler A compiler is a translator used to convert high-level programming language to low- level programming language.
It converts the whole program in one session and reports errors detected after the conversion.
Interpreter Just like a compiler, it is a translator used to convert high-level programming language to low-level programming language.
It converts the program one at a time and reports errors detected at once, while doing the conversion.
Assembler An assembler is a translator used to translate assembly language to machine language.
Assembly language is difficult to understand as it is a low-level programming language.
Difference between Compiler and Interpreter: