keyword in C and C++, it's just used to rename datatypes, right? That's all I've ever used it for. Anyway, typedef is useful, but I think that many C and C++ APIs severely over use it. For example, ...

Structures (or “structs” in C) allow you to group several related variables and treat them as one unit. They are a mechanism for extending the type system of the C language by introducing user-defined ...