How can I check that domain name (web server) resolves?
You can quickly check if a website is accessible by doing a ping command. This will send a small package of data to the IP address to which the domain is configured, and wait for an answer:
If you get a response, you see the assigned IP address as well. If you do not get a response or a response from a different IP address, you may need to debug.
Tip: not all servers respond to a ping command. The absence of a response does not necessarily mean that the domain is not available. It may be perfectly available in a browser.
Tip: the other way around, a response to a ping command does not mean that the website can be reached in a browser. There may be no website at all, the web server may be misconfigured, the page may contain errors.