2.3.1.2 State the functions of OS

The main functions of OS are (1) starting a computer; (2) providing a user interface; (3) managing data & program; (4) managing memory; & (5) configuring devices.
Starting the Computer
OS is used to start the computer. This process is called booting - to load & initialize the os. It can happen in two ways: warm boot or cold boot.
A warm boot means restarting a computer that is already on - usually after installing a new software or hardware or after an application crashes or stops working.
A cold boot means starting a computer that is already off @ completely powered off.
Providing a User Interface
This function controls how the user enters data and instruction & how information is displayed. The three type of user interface are (1) Command-Line; (2) Menu-Driven; & (3) Graphical User Interface . The user interface typically enables users:

• to start an application program
• to manage disks and files such as formatting, copying & renaming
• to shut down the computer safely by following the correct procedures

Managing Data & Programs
When we start an application, the CPU loads the application from storage into memory. In the early days, single-tasking OS could run only one application at a time. Multitasking os enable users to work with two or more application programs at the same time.
Managing Memory
The computer's OS is responsible for managing memory such as:

• optimizing the use of RAM
• allocating data & instruction to an area of memory while being processed·
• monitoring the contents of memory
• releasing data & instructions from being monitored in memory when the process is done

Configuring Devices
Another function of an OS is handling & enabling communication with input and output devices. Most OS come with drivers for popular input & output devices. These drivers install new devices & check whenever there is conflict with these devices.