The standard template library (STL) is the heart of the C++ standard library. The STL is a generic library that provides solutions to managing collections of data with efficient algorithms.

The main components of STL that are provided to us as programming tools are algorithms and containers.

Usually, if we want to support A algorithms and C containers, we’d need A × C implementation. (For each container c, we would have to implement A algorithms.)

One solution to this is to use polymorphism. But it would decrease efficiency.

STL’s solution to this problem is to use iterators. Each container is required to provide iterators and each algorithm is implemented to work with iterators. As a result, STL needs to provide only A + C implementations for A algorithms and C containers.

There are many reasons to use the STL, so use it whenever you can in C++!