In single user operating system, only a single user can access the computer at a particular time.
The computer, that is based on this operating system, has only single processor and executes only a single program at all the time.
This system provides all the resources such as CPU, I/O devices to a single user at all the time. Single user operating system is of two types:
Single user, single-tasking operating system
Single user, multi-tasking operating system
The Single User, Single-tasking operating system as a single user to execute one program at a particular time. For example, MS-DOS and Palm OS for Palm handheld computers are single user, single tasking OS.
The Single User, Multi-tasking operating system allows a single user to execute multiple programs at a same time. For example, a user can perform different tasks such as making calculations in Excel sheet, printing a word document and download a file from the internet at the same time.
The main disadvantage of this operating system is that CPU sits idle for most of the time and is not utilized to its maximum.
