what is iostream and what is it used for

Answer 1

it is a class defined in the header file iostream.h or iostream

this class (input output stream) can control the output screen in the console that you see as output (in pc)

it has four objects through which you do stuff
cout
cin
cerr
clog

first two are necessary but if you wanna go in detail then refer http://www.cplusplus.com/reference/iostream/

Answer 2

input output stream

Answer 3

thank you very much for your answer

Answer 4

iostream is a header file used in c++

Answer 5

it's a header file with is use for input and output and also called as pre processor file.

Answer 6

*which