What's the meaning of the namespace

Answer 1

https://www.sololearn.com/discuss/294730/?ref=app
https://www.sololearn.com/discuss/333555/?ref=app
https://www.sololearn.com/discuss/570114/?ref=app

Answer 2

namespaces helps to shorten codes. For example:

instead of this:

stdout::cout << "hello world!" << endl

by using namespaces like

using namespace std;

the code becomes simpler like this:
cout << "hello world!" << endl

Answer 3

you can do
namespace a {
void print(){
cout << "a";
}
}
namespace b {
void print(){
cout << "b";
}
}
and now you can call
a::print (); // a
b::print (); // b

or

using namespace a;
...
print(); //a

[edit]
the std namespace contains all C++ standard functions, classes, etc (only C++ headers like iostream, string, etc.. C headers like stdio.h (cstdio) or time.h (ctime) don't use namespace because C doesn't support namespace)