Basic OS related terms

1. Single tasking

The ability of an OS to perform only one task at a time
2. Multitasking
The ability of an OS you perform multiple tasks at the same time
3. Multi user
An OS that supports multiple users gives different user profiles and workspaces for each user.
4. Single user
A single user OS only supports one user and personal configuration
5. Boot
Operation required to start a computer in its normal operating configuration.
6. Kernel
The part of an OS that connects hardware and software.
7. Defragment disk
When file pieces are joined together.
8. Disk format
When a storage device is blanked and features changing it´s working format. 
9. User profiles
Collection of data associated to an user.
10. Logs
Registry where every action is logged (saved)