You are somewhat confused about the different parts of the URL. Let me break them out for you:
https is the protocol
www is the subdomain
example.com is the domain name
com is the top level domain
/path is the URL path
How can URLs have a dot . at the end, e.g. www.bla.de.? is about the domain name ending in a
example.com.). That situation can happen, but it isn't common, and isn't something most webmasters ever worry about.
The subdomain (
www) is always separated from the domain name by a
.. So I guess in a sense, the subdomain can "end" in a dot, but that is really just more separation from the domain name. On an internal network where you have your computers DNS "search domain" set as "example.com", you could access
http://www.example.com/ with just
http://www/. The "example.com" part would be assumed. The trailing dot on
www.example.com. tells the DNS system not to use the search domain to be doubly sure that it doesn't assume
www.example.com.example.com. Putting in
http://www./ wouldn't be able to acces your site because it tells the DNS system not to use the search domain and treat
www as a top level domain (which would then not be found).
You are free to define the URL path for your website any way that you want as long as you can get your web server to support it. All of the following URL paths would be valid and each would be different:
The trailing dot has no special meaning there. Most web servers would just treat it as part of the file name.