An author URL display all posts associated to a particular author.
This feature help to change the default /author/ endpoint to something customized. The /author/ slug is common to WordPress, is an easy way for a hacker boot to attempt and identify the site as using WordPress.
As default the author url format is:
By using the option “contributor” the default url becomes:
Block default author url
After changing the default author, the old url is still accessible. This provide a way to block it and allows only the new one.