The difference between a 301 and 302 URL redirect
I read this article about redirecting domains and also get asked this every once in awhile by customers: what is the difference between a regular “URL Redirect” (basically one done with a “302 Found” header) and a “301 Redirect” (done via a “301 Moved Permanently” header)?
The main thing to understand is that a 301 redirect indicates that the condition should be treated as a permanent condition, while the other kind (302, or “follow” or “found”) indicates the possibility of a temporary condition.
The distinction is important because of the way search engines interpret these result codes. Basically a search engine encountering a 301 redirect will take any page relevance or “pagerank” it has associated with the URLĀ or domain being redirected, and assign that relevance to the destination URL. They will not do this for the other type of redirect (because the condition may be temporary).
Domainers in particular should be aware of this, especially if they have a domain with some relevance in search engines and the decide for whatever reason to redirect that domain to an external site (like an affiliate or CPA program), if they use a 301 then they will dissipate any pagerank their domain has and give it to the destination URL.