It happens all the time on other sites, people change the way the site is setup, the permalinks, the urls, etc. and your links to them break. But, what about your site? Do you move things? Update them and change the URL? If you do, you may be breaking connections from others to your site.
Yes, the serious geek knows how to mess around and set up redirects- there is even a place to set them up in cpanel, but, this Redirection plugin will allow the novice do it from the WordPress interface!
Redirection – Manage 301 redirections without modifying Apache | Urban Giraffe
Redirection is a WordPress plugin to manage 301 redirections, keep track of 404 errors, and generally tidy up any loose ends your site may have. This is particularly useful if you are migrating pages from an old website, or are changing the directory of your WordPress installation.
Our general advice is don’t move things, don’t change your permalinks, but if you do, this is the tool.