A scope is a tool used to enhance vision, often attached to firearms, cameras, or telescopes. It helps users see distant objects more clearly by magnifying them. In the context of firearms, scopes improve accuracy by allowing shooters to aim more precisely at their targets. In programming, "scope" refers to the visibility and lifetime of variables within a code. It determines where a variable can be accessed or modified. There are different types of scopes, such as global and local, which define how and where variables can be used within a program.