Search Engine Friendly URLs (SEF)

Clean URLS (or search engine friendly urls) are just that – easy to read,
simple. You do not need clean urls in a site architecture for Google to
spider a site successfully (Update 23/9/08 – apparently confirmed by
Google), although I do use clean urls as a default these days, and have done
so for years.
The thinking is that you might get a boost in Google SERPS if your URLS are
clean – because you are using keywords in the actual page name instead of a
parameter or ID number. Google might reward the page some sort of
relevance because of the actual file / page name.
Google does reward pages with keywords in the url, and they can also form
part of a link to your site if shared in a forum, for instance.
Sometimes I will remove the stop-words from a url and leave the important
keywords as the page title because a lot of forums garble a url to shorten it.
It should be remembered it is thought although Googlebot can crawl sites with
dynamic URLs, it is assumed by many webmasters there is a greater risk that
it will give up if the urls are deemed not important and contain multiple
variables and session IDs (theory).
As standard, I use clean URLS where possible on new sites these days, and
try to keep the URLS as simple as possible and do not obsess about it. That’s
my aim at all times when I seo – simplicity.
Be aware though – Google does look at keywords in the URL even in a
granular level.