In a day of laptops and remote systems, it's often impractical to keep the same ssh session going to a specific server indefinitely. There are times when I want to reconnect from home to an ssh session that I started at work. Unfortunately, ssh doesn't support that sort of thing. But the screen utility lets you do something similar to this.

Screen is great for letting you start a terminal session, walk away from it, and then come back later. Maybe you need to start a long running process such as a complicated data conversion or a multi-hour build. You can use screen to start the ball rolling, go home, and resume the already-in-progress and uninterrupted activity that you started at work.

What screen is and does