Accessing or controlling a computer that you are not physically in front of.
Remote access is where the user controlling or accessing a computer or server, is not physically located in the same place as the computer or terminal they are using.
- Enabling remote access for another account on Mac remotely via SSH
 - Remote desktop from a Windows machine into a Redhat box
 
Security implications
Remote access is a common security issue, because it opens doors for an attacker that allow them to do whatever they want on your computer if they get in, without any need to physically access the computer.