In C++, the Standard Template Library (STL) is all in the namespace std so that it doesn't conflict with other definitions. <vector> is the standard include file for STL's vector container. <vector.h> is a deprecated (old) include file that some compilers provide for compatibility with programs written before the C++ standard came out. Never use this in new programs you write.
Originally posted by LudaLuda I noticed my usage of #include<vector> requires me to use the namespace std, why ?
what is the difference between #include<vector.h> and #include<vector>