Dynamic Host Configuration Protocol (DHCP)
Every device on a network needs a unique IP address. While these addresses can be manually assigned that is not practical as we move from one network to another. A DHCP server provides an automatic assignment of an IP address for each device that requests to join a network. A DHCP server is required on a IPv4 network, however, IPv6 is not dependent on a DHCP server.
Domain Name System (DNS)
Note: DNS can often refer to Domain Name Server – which is an individual server which provides the access to the Domain Name System.
All devices on a network have an individual IP address. These IP addresses are very difficult for users to remember, and they can sometimes change. The domain name system attaches IP addresses to a hostname, the host name (or domain name) is easier for users to remember. Think of it as a local phone book, but one that can access a worldwide phone book when it doesn’t have the necessary number.
When you type in a domain name in a browser – such as google.com your computer will go to the local Domain Name Server asking for the correct IP address. If the DNS server has the IP address it will provide it to your computer which will then use it to connect to the website. If the local DNS server does not have the hostname it will go to another DNS server until it finds the hostname and iP address.