SSH (Secure SHell) is possibly the best way to remotely access a Unix system – it's very secure thanks to automatic encryption of all the traffic, and it's also quite universal because you can do all sorts of things: access remote command line shell, forward graphics session output, establish network tunnels, set up port redirections and even transfer files over the encrypted session.
Today I'm going to show you how to get started with SSH in Ubuntu.
Installing SSH server in Ubuntu
By default, your (desktop) system will have no SSH service enabled, which means you won't be able to connect to it remotely using SSH protocol (TCP port 22). This makes installing SSH server one of the first post-install steps on your brand new Ubuntu.
The most common SSH implementation is OpenSSH. Although there are alternative implementations (closed source solutions and binary distributions maintained by various Unix and Unix-like OS vendors), OpenSSH is a de-facto standard in the secure transfers and connections industry. That's exactly what you want to install.