A server on a network - standalone or member - can function in a number of roles. As the needs of your computing environment change, you may want to change the role of a server. By using the Server Manager and the Add Roles Wizard, you can install Active Directory Domain Servers to promote a member server to a domain controller, or you can install individual roles or combinations of various roles, such as DHCP, WINS, and DNS.
When your web browser or email program connects to another computer on the Internet, it does so through a TCP/IP port. If you have a web server or FTP server running on your PC, it opens a port through which other computers can connect to those services. Port numbers are used to distinguish one network service from another.
Ethernet is one of the oldest and most established network technologies. When we talk of Ethernet, we refer to wired networks - all the computers on the network are connected by cabling to a central hub or router.
If you use an Ethernet or Wi-Fi connection to access your network, you might find that Ubuntu spends a few seconds during each boot acquiring an Internet address. This will be characterized by a long pause while nothing seems to be happening. Therefore, one way to provide an instant speed boost is to give your computer a static IP address.