Discussion on: Error due to (.) in Domain Name End[www.ashish.com.]

That's just how DNS works. The trailing dot means that the hostname is an absolute path and not relative to your current local domain.

If your local network is called "example.local", you could setup a local DNS server in your network, to resolve "google.com" to a device in your local network.

Entering "google.com" in your browser will then be the same as entering "google.com.example.local" and you won't be able to access Google anymore.
That's basicly the same as having a computer with the hostname "my-computer" in your network - you can access a running webserver by typing in "my-computer" into your webbrowser, effectively navigating to "my-computer.example.local".

Adding the trailing dot to the URL as in "google.com." tells the DNS server, that you didn't left out the "example.local" due to laziness, but because you want, in fact, navigate to "google.com" and not to "google.com.example.local".

You can think of it as relative and absolute paths on your computer.
On a Unix-based operating system, a file path starting with a slash will be an absolute path, while paths without a leading slash will be treated as relative to your current working directory.

Summary:
google.com --> relative to your current domain
google.com. --> absolute to the top-level domain