This is also known as a permanent redirect. You can use a 301 redirect to direct your visitor to the new page or site that you’ve moved permanently. This is to tell Google or other search engines that your original page is no longer valid and in use and would like them to de-index it so that they can pass all the link juice to your newly redirected page or site. A 301 redirect is extremely useful when you want ensure that anyone that has bookmarked your old web address will automatically be directed to the new one.
Don’t mistaken this with the 301 redirect. Basically a 302 redirect is a temporary redirect. In other words, if your content is temporarily moved to a new page or site, you can use a 302 redirect to tell the search engines to redirect your visitors to this new location. This is to ensure that they do not pass the link juice and the anchor text over to this new place because sooner or later, your original page or site will resume back to its original establishment.