Variables of this type can only take two values- 1 and 0. In C++ these correspond to true and false and can be used interchangably. In C# bool variables can only use true and false, they are not interchangeable with 1 and 0.
Boolean variables can be packed together to save memory space. An understanding of binary can be a useful skill.
Note Because of the way false and 0 are usually treated the same (except in C#), any non zero value is the same as true, not just 1.

