URL changes. The old URL is no longer accessible. You need to redirect all traffic to the new URL. This is done using URL redirection. There could be various reasons to use a URL redirection. A 301 redirect would mean that you have permanently moved your website to a new domain and website visitors will be redirected to the new URL.
So, are 301 redirects a good SEO practice? Search engines do not place a penalty for a 301 redirects. However, there are some lows of using this. Search engines take some time to recognize a redirect, recheck the credibility of the previous site and then assign a new “value” or ranking to the destination website. Other than that, 301 is a good SEO practice, it helps users and search engines you’re your new URL. Unless you are redirecting to manipulate search engines and users to land on some irrelevant and spammy pages, you can use 301 redirects without any negative effects!