Periods have a special meaning in URLs – they signify a domain or file-type extension. Example:
https://www.example.com/path/to/resource.html
“https://” is the protocol.
“www.” – not really needed
“example” – name of the domain (website)
“.com” – TLD (top-level domain)
Other periods in the URL would cause problems as they would indicate a change in domain or the start of the file-type extension of the resource. See https://en.wikipedia.org/wiki/Uniform_Resource_Locator for more information.
In WordPress you can set it up so that the URL of a page would be https://example.com/name_of_post or https://example.com/name-of-post
To do this, go to your permalink settings and select the “post-name” setting and click save. Now all your posts (and pages) can be reached at, “yoursite.com/name-of-post”. Then it’s just a matter of naming your pages/posts the way you want (but again, no periods).
Hope this helps.