I have a new drupal site,it was built by other website designer.Now i got a problem for the url.There are some different url with same information.For example: "/taxonomy/term/31/0" and "/projects/led-tunnel-lighting".I only need the url like "/projects/led-tunnel-lighting". Please tell me how to fix this problem.Thank you very much! I was a novice of drupal.
I believe your two URLs are the same, but one is the system URL and the other one the aliases URL. They are both valid and normal to have, but in that case what you need is this module: Global Redirect
an alias provides a nice clean URL for a path on a site. However Drupal does not remove the old path (eg node/1234). The problem is that you now have two URLs representing the same content.
Whenever you need to link to a node or a term (or something else in which might have an URL-Alias), use the l() function. The link to the term will then be rewritten to the given URL-Alias (as long as there is one).