The menu displayed when right clicking a screen object such as a file/folder name, icon, word or highlighted text. The "context" means the menu relates to the object selected (example below). See
right click,
context sensitive help and
Menu key.
Right Click Windows Recycle Bin
Right clicking the recycle bin displays options in the context menu.
Right Click Highlighted Text in a Mac
After highlighting text from a newspaper article (pink background), right clicking displays options for that text in the context menu.