Earlier in C, encapsulation is meant to hide the information. Encapsulation is included in C by making other class members static in a class to prevent accessing the members by another module. However, the concept of multiple instances is not supported by the encapsulation because it is impossible to directly make multiple instances inside the static class module. If there is a need of multiple instances, a struct is used. On the CONTRARY, encapsulation is not supported by structs.
In C++, a class supports both encapsulation and multiple instances. The class's interface that contains the public MEMBER functions and friend functions of the class can be accessed by multiple users. On the other hand, an implementation of the class is defined by the private and protected parts of a class. This encapsulated part forms a struct; thereby, reducing the TRADEOFF (loosing of ONE quality as a result of gaining of another quality) between the encapsulation and usability.

Earlier in C, encapsulation is meant to hide the information. Encapsulation is included in C by making other class members static in a class to prevent accessing the members by another module. However, the concept of multiple instances is not supported by the encapsulation because it is impossible to directly make multiple instances inside the static class module. If there is a need of multiple instances, a struct is used. On the contrary, encapsulation is not supported by structs.
In C++, a class supports both encapsulation and multiple instances. The class's interface that contains the public member functions and friend functions of the class can be accessed by multiple users. On the other hand, an implementation of the class is defined by the private and protected parts of a class. This encapsulated part forms a struct; thereby, reducing the tradeoff (loosing of one quality as a result of gaining of another quality) between the encapsulation and usability.