DNS is a hierarchy.
As part of the hierarchy you can have subdomains.
Like, a lot of them, to, like, help organize things and stuff.
If your company produces movies you could have movies.company.com.
Then craptastic.movies.company.com for your latest thriller, “Craptastic.”
Or, maybe you could avoid DNS altogether and have:
http://movies.company.com/craptastic. Or
http://company.com/movies/craptastic. Like, ohmygod!
Also, if you have company.com then the name companymail.company.com is redundant and idiotic.
No, really. It is. A simple test is if I have to type the same string of characters twice in a domain name you’re doing something wrong.
Okay, that’s out of my system. Thanks for listening.