In this first part, Stephan introduces STL and then demonstrates many of its core features (iterators, algorithms, and data structures). As is Stephan's nature, he elaborates on technical details in very substantive way. The Standard Template Library, or STL, is a C++ library of container classes, algorithms, and iterators. STL provides many fundamental algorithms and data structures. The STL is a general purpose library: its components are heavily parameterized such that almost every component in the STL is a template. This is not an introductory series on C++. As such, it is expected that viewers already possess a working knowledge of the C++ language.