The question\'s pretty self-explanatory really. I know vaguely about vectors in maths, but I don\'t really see the link to C++ vectors.
It's called a vector because Alex Stepanov, the designer of the Standard Template Library, was looking for a name to distinguish it from built-in arrays. He admits now that he made a mistake, because mathematics already uses the term 'vector' for a fixed-length sequence of numbers. C++11 compounds this mistake by introducing a class 'array' that behaves similarly to a mathematical vector.
Alex's lesson: be very careful every time you name something.