The C++ Standard Library function std::back_inserter is a helpful tool for inserting elements into containers. These containers can be std::vectors, std::deques, or any other container that can do the push_back action. It is a component of the header and is frequently used with the std::copy, std::transform, and std::for_each Standard Template Library (STL) algorithms.

The main goal of std::back_inserter is to make it easier to add components to the end of a container without requiring manual memory allocation and size management of the container. When combined with algorithms, it generates a unique iterator that inserts elements automatically by using the container's push_back function. It is helpful for filling a container during data processing or modification operations.