is DHCP server important?
It is when you’d like to serve DHCP leases to DHCP clients?
You’re not asking a good question. That’s like going to a car forum and asking “are car doors important”. Yeah, probably. You can drive a car without doors. On the other hand you’d usually like to have doors on your car.
But just as a question without any context it doesn’t make any sense.
Fewi, it was a rhetorical question. 
I don’t get it.