Computer System

The software required to make a computer functional is the operating system. It is the most basic system software.

Its two primary functions are:
1. It manages the other application programs.
2. It provides access and security to the users of the system.

It also acts as an interface between the user and the computer.

RAM is needed because programs and data must be loaded into main memory before processing. The CPU interacts directly with RAM, so it helps the computer work quickly.

Difference between RAM and ROM:
- RAM is volatile: its contents are lost when power is turned off.
- ROM is non-volatile: its contents are not lost when power is turned off.
- RAM is used for temporary storage while the computer is working.
- ROM is used for permanent storage of rarely changed instructions, such as the boot loader.

The need for secondary memory is to store data, instructions, and results permanently for future use.

Primary memory is limited and RAM is temporary, so secondary memory is used when we need:
- larger storage capacity
- non-volatile storage
- data retention even after power is off

Examples include HDD, CD/DVD, memory card, SSD, and pen drive.

Proprietary software is software that must be purchased from the vendor who owns its copyright. Its source code is generally not freely available.

Freeware is software that is freely available for use, but its source code may not be available.

Two proprietary software examples:
- Microsoft Windows
- Tally

Two freeware examples:
- Skype
- Adobe Reader

Browsers used for browsing the internet include Mozilla Firefox, Google Chrome, Microsoft Edge, and Opera. Any one or more of these can be named.