DHCP in Networking

Dynamic Host Configuration Protocol

Two questions:

1. When we add a computer to a network, what is the IP address it is going to get?
2. What is the DNS server in the network?

We can either manually assign IP addresses to these computers and then manually configure the DNS for it

OR 

We can automate it and that is where DHCP comes into play, it automatically assigns an IP address to the computer that has been newly added to the network and manages the DNS related options for it.