Every domain name has a suffix that indicates which top level domain (TLD) it belongs to.
Example for TLDs:
.edu - Educational institutions (gTLD)
.org - Nonprofit organisations (gTLD)
.mil - Military (gTLD)
.com - commercial business (gTLD)
.net - Network organizations (gTLD)
.fi - Finland (ccTLD)
.vodka (new TLD)
gTLD - Generic Top-Level Domain.
ccTLD - Country Code Top-Level Domain