Any body plz help me...

Answer 1

Std means standard. Basically, cin and cout belongs to the namespace std.

This is a shortcut (if you don't add this to the beginning of your code, you'll have to write std::cout instead of cout) that is used to prevent troubles if two methods have the same name.

Answer 2

For... What ?

Answer 3

Sorry I can't explain that (I don't use c++)

Answer 4

What we used
Using namespace std;
Explains bro

Answer 5

I'm beginner i am just learning now c++

Answer 6

Ok thanks