The search engine Google has a ton of different operators you can use to find stuff faster and easier. I will say up front that only the very few have all of them committed to memory (and if you do, you use Google way too much). No, you don’t have to know all of them. However there are a few you can commit to memory that will help you out quite a bit.

site:

This is a query modifier. In plain English this means "search [this] specific site for [this word/phrase]".

For example, if you wanted to search pcmech.com via Google for the word computer, the Google search is:

computer site:pcmech.com

You don’t have to use www. Just the domain (that being pcmech.com).

Here’s another example:

stayin’ alive lyircs site:lyricsfreak.com

This will search the site lyricsfreak.com for the lyrics to the song Stayin’ Alive.

define:, what is, what are

In plain English this is a dictionary search via Google.

Example:

define:computer

or

what is computer

or

what are computers

Google will go out and find a definition for the word computer.

Note, define: is the best one to use.

weather

A quick way to get a weather forecast from Google.

Example:

weather Tampa FL

or

weather 33617

Note that there is no colon sign (:) with the weather command.

If you want to see the huge list of stuff you can do with Google, a comprehensive guide is here.