HTTP redirect codes for SEO explained
What are redirects?
Redirects are a way to forward visitors and search engines to a different URL than the one they requested. Redirects play an important role within SEO, so it's important to know what types of redirects there are, when to use which ones, and how they measure up against one another.
Redirects are important for both visitors and search engines when content has moved:
Visitors: you want to offer visitors a great user experience on your website. When they're requesting content that was previously available on URL A, you don't want them to hit a 404-page. You want them to be redirected to URL B.
Search engines: you want search engines to understand that content has moved, and whether it's temporary or permanent. Giving search engines the right signals is essential to your SEO performance.
When to use redirects
You use redirects when you're moving content around and you want the content to retain its value.
The scope differs; you could just be moving one page or you could be migrating an entire website to a different domain.
Website redirect: when it's about an entire website
Domain redirects are used when entire domains are affected.
Example: switching domain names
Say you're moving your website over to a new domain name, then you need to redirect both visitors and search engines there. Redirection is done on a web server level, and it's similar to redirecting URLs, the scope of the redirect is just very different — it affects the whole website.
Example: merging websites
Another example where you'd use a website redirect is when merging websites; this involves one or more websites that are merged into one. This is common after acquisitions, or when satellite websites cease to exist.