This is an old revision of the document!
screen Terminology
session A screen session is a single collection of windows all running with the same grouping. Copy and paste only work within a particular session, and all window numbers within each session are unique. There is a single master screen process for each session.
window A session can contain multiple windows. Each window can run a different program (by default, windows are created running a shell). Each window has a number unique within that session. It also has a name, which does not have to be unique.
region A splitting of the current display into multiple areas that can be viewed at the same time. Each region provides a view into one of screen's windows.
display This refers to where the screen session is attached; if being specific, it refers to the terminal or pseudoterminal used by the attaching process.
display terminal The terminal to which screen is attached. Often an xterm or console window, but could be any terminal, either physical or software.
virtual terminal The terminal that screen windows provide to the programs running within them.