To describe various functions when using computers we can use phrasal verbs. Here are some of the most commonly used phrasal verbs related to computers.
1. to boot up - to load (an operating system) and start the initial processes.

2. to key into - to enter (data) into a computer by means of a keyboard.

3. to type in - to write in by means of a keyboard with types.

4. to back up - to make a backup of (a program or file).

5. to switch on - to turn on, to start.

6. to switch off - to turn off.

7. to print out - (of a computer output device, such as a line printer) to produce (printed information).

8. to power up - to switch on the power to (a computer system).

9. to connect up - to establish telephone communications with or between.

10. to log on/in - to enter a computer, system.

11. to log off - to exit a computer, system.

12. to shut down - to cease to operate or cause to cease operating.

13. to hack into - to break into another computer, system or server.

14. to go down - to stop operating.
Some examples:
Please print out for me this document, but first you have to power up the computer, because I yesterday it went down and I had to boot it up. Then when you switch it on and you log in. When you finish printing, please shut down the computer.