Header files in C++ . Why different people write different kind of header files?

Question

Header files that we write in the beginning of C++ program differ with the compiler or software that we use to write a c++ program ?

Answer 1

Some compilers may provide support to deprecated headers which were used during pre-standard C++. Still, headers are included only when needed, e.g. <cmath>, <algorithm>, etc. Hence, different programs will appear to include different headers.

Answer 2

it's dipending on compiler