Samba is long for SMB which is short for Server Message Block which is also known as Windows Networking. Samba enables, among many things, a Linux machine to be a peer member of a Microsoft Windows network. This case describes the process using Ubuntu Linux.
Although it is one of the options available when installing an Ubuntu server, you can add it later with "tasksel" at the command line (Applications, Accessories, Terminal)
sudo tasksel
All the machines on the network need names and IP addresses. The simplest mechanism to mapping addresses to names is to edit the "hosts" file. On Ubuntu that file is /etc/hosts. My home network has four machines, a router and a printer. My hosts file looks like this: