WordPress Permalinks, first key to make your site SEO friendly. But wordpress by default uses the permalinks structures such as
/%year%/%monthnum%/%day%/%postname%/
and this is not really a good idea cause it will return your topics url which will look like this below
http://www.abc.com/2008/07/31/your-post-slug/
And say for the instance you’ve already has a handful of topics that has been posted for a while and google has indexed it. So now you want to change your WordPress Permalinks to a much more friendly url settings such as
http://www.abc.com/your-post-slug/
Yes you can easily upgrade your structure from WordPress Admin options but all the links indexed by google wont be able to land on the proper topics.
Read moreHow to Change WordPress Permalinks without affecting Google