Why we type using name space std , not conio.h

Question

what about conio.h,we r typing using name space STD, what it means

Answer 1

using namespace std
That means we're using every function under a namespace calles std. There are a specific topic about namespace you should learn about this.
std itself is a modern c++ standard where every aspect of the language are standarized across compiler and architecture,so there wont be any conflict or missing feature when try to port the code directly.

Why not conio.h ? Conio itself is not a standard, its only(cmiiw) available in windows. That means anyone else with who are not using windows unable to compile the code.thats why iostream with namespace std are more prefferable

Answer 2

Thanks