The 301 Status Code means that a page has permanently moved to a new location.
The best SEO (Search Engine Optimization) practice for URL redirection is a Server-Side 301 Redirect. It ensures that users and search engines are directed to the correct page and you will not dilute your PageRank.
All other redirect techniques (302, meta refresh, etc.) will decrease your link power in search engines (and particularly in Google). 301 Redirect passes the same amount of PageRank.
Hint: People access your site through several different URLs. If, for example, your home page can be reached in multiple ways - for instance, http://example.com/home, http://home.example.com, or http://www.example.com - it’s a good idea to pick one of those URLs as your preferred (canonical) destination, and use 301 Redirect to send traffic from the other URLs to your preferred URL.