Use of using namespace

sir,why should we use using namespace std statement.even it is considered as a bad practice.why should use (std::slight_smile: before every type
for example:- std::cout<<“hello world !!”<<endl;

@manikantahariharan434 https://www.geeksforgeeks.org/using-namespace-std-considered-bad-practice/

Read this article. It is explained here.