Google just published an updated document that goes over six different types of URL redirects and their effects on search results. Google's Gary Illyes and Lizzi Harvey worked together to add eight pages of content to an existing help page on 301 redirects. At only five paragraphs in length, the previous version of Google's help guide was scant on details. Now the guide has information on each type of redirect, examples of what they look like, and details on how they impact Google Search. Here's a summary of the newly added information:
Types of Redirects & Impact on Google Search
The difference between redirects is undetectable to visitors, but Google treats them differently in terms of the strength of signals sent to the target URL. Redirects fall into one of two categories -- temporary or permanent. Google uses a permanent redirect as a strong signal that the target URL should be the one shown in search results. Conversely, Google uses a temporary redirect as a weak signal that the redirect target should be the URL shown in search results.