Q:  On a SERP, what does the different coloured text represent?
Eric

Well Eric, that's a very good question. It's well worth getting to know what a search engine's results page represents and the information that gets displayed within them.

Lets dive right in and take a look at what information is displayed in a search engines results page.

Page results
This tells you an approximate amount of pages a search engine has in its index that match a particular term. This can be a handy indicator of competition for particular terms and can also tell you how many pages you have in the search engine's index when conducting a site: operator.

For some queries you will also notice that Google has added a definition link so you're able to see what that word means. Example

Page title
(the blue writing)
The blue writing is the first thing most people see. This is pulled from the title of your page or your 'title tag'.

Description tag
(the black writing)
The black writing gives users a little more info about your pages. Typically this information is pulled from your description tag and also your page content should a search query match some of the content on your page.

The important thing to remember here is that you can influence what people read in this area through your description tag. Like your title tag, it's an opportunity to write a great advert that will make people want to click on your listing.

URL
(the green writing)
The URL of your most relevant page to a search query will show underneath the description of a a page. This doesn't have too much impact on click through rates etc and if you want to be able to change or manage your URL structures (ie have www.blah.com.au/sunnies instead of www.blah.com.au/index.asp?pageid=14?itemid-10 ) this will depend on your content management system or how your site has been built.

Eric, I hope this gives you a clear idea of what you see on a search engines results page and how this then translates back to your website.