"Behind" refers to a position that is at the back of something or someone. It can indicate a physical location, such as standing behind a tree or a person. The term can also describe a situation where one thing is less advanced or developed than another, such as being behind in a race or in schoolwork. In a broader context, "behind" can imply support or influence, as in being behind a project or a movement. It suggests that there are efforts or motivations that are not immediately visible but play a crucial role in the success or progress of something.