This is a special kind of object, which maintains some contextual state information when it is created.
It can behave like a function, but is a kind of function wrapper that references a function and a scope. Since it inherits everything from the Function object, it can behave like a function and can be called as such.
Because it also stores the scope chain at the time it is manufactured, it can restore that scope chain when it is executed.
|See also:||Lexical scoping|