The standard C++ library has a sequence of container classes. The container classes are robust and support C++ programmers to control common programming operations. There are three types of STL container classes. They are sequence, associative, and derived containers. Sequence containers are developed to allow sequential and random access to all the members. Associative containers are expanded to get their elements by values. Derived containers such as stacks, queues, and priority queues can be created from various sequence containers. Containers are shown in Figure 20.1.
Fig. 20.1 Classification of containers