In C++, a struct is a user-defined data type that allows you to group several related variables of different data types into a single unit under one name. It is similar to a class in that both hold a collection of data of different data types, but the default visibility of members is different: class members are private by default, whereas struct members are public by default). To create a struct, you use the struct keyword followed by an identifier (name of the structure) and declare one or more members (variables inside curly braces) of that structure. You can access the members of a structure variable using the dot (.) operator. Unlike arrays, structures can contain many different data types.