The meaning of some verbs with particle (often called phrasal verbs) can be easily understood from its two parts.

Look at the photos.

A network consists of two or more…

Separate networks are linked over a public network, the Internet.

However, many phrasal verbs have an idiomatic meaning, not predictable from the meaning of its parts. e.g. carry (= transport); carry out (= execute)

Computers carry out the programs.

Certain particles have similar meanings, regardless of the verb (on/off, in/out, etc.).

turn on / switch on (= starts the operation of something)

turn off / switch off (= stops the operation of something)

Other common phrasal verbs in computing include:

• plug into (=connect):

  Plug one end of the phone cord into the phone jack.

• set up (= establish):

  What do I need to set up a wireless LAN?

• sign up (= register, enroll in a service)

  Once connected, you can sign up for RSS feeds, newsletters, etc.

• try out (= test or use experimentally)

  You can try out new software on their site.

• find out (= learn, discover)

  Search the Web to find out more information about WiMAX.

• take up (= occupy)

  Fibre optic cables take up less space than copper cables.

• make up (= constitute, form)

  Several LANs connected make up a WAN.

• fill in (= write the necessary information)

  You need to fill in this online form.

When the verb has a preposition associated with it, the preposition must precede the object:

You can look for information on the Web. (not: look information for)

Separate networks are linked over a public network, the Internet.

When the particle is an adverb, it can precede or follow the direct object:

You need to type in your username. OR … type your username in.

You can look up words in a dictionary. OR … look words up in a dictionary.

Turn on the computer. OR Turn the computer on.

If a direct object is a pronoun, the particle must follow it.

You need to type it in. (not: type in it)