Before we look at simple and incredibly common errors like 404s, let's address the idea of redirecting requests, something that's very common. Although not always for reasons that are evident or tangible for the average user.
So we might we want to redirect requests to another request? Well there are quite a few reasons, as defined by the HTTP specification that could lead us to implement automatic redirects on any given request. Here are a few of them with their corresponding HTTP status codes:
A non-canonical address may need to be redirected to the canonical one for SEO purposes or for changes in site architecture. This is handled by 301 Moved Permanently or 302 Found.
Redirecting after a successful or unsuccessful
POST. This helps us to prevent re-POSTing of the same form data accidentally. Typically, this is defined by 307 Temporary Redirect.The page is not necessarily missing, but it now lives in another location. This is handled by the status code 301 Moved Permanently...