A 301 redirect is a permanent redirect which passes most of the link juice (ranking power is SEO) to the redirected page. 301 refers to the HTTP status code for this type. In most instances, the 301 redirect is the best method for implementing redirects on a website. There are also many other types of redirects that I won’t be covering in this blog article.
If you are using WordPress their are many extremely useful plug ins to help you manage these redirects as well as detecting broken pages so you can fix them. The plug in I recently discovered is the SEO Redirection Plugin it will detect broken pages and let you redirect them to the correct page, or simply route it back to the home page.
I hope this was a short and sweet explanation! :)