emplace vs insert in C++ STL

// C++ code to demonstrate difference between
// emplace and insert
#include<bits/stdc++.h>
using namespace std;
 
int main()
{
    // declaring map
    multiset<pair<char, int>> ms;
     
    // using emplace() to insert pair in-place
    ms.emplace('a', 24);
     
    // Below line would not compile
    // ms.insert('b', 25);    
     
    // using insert() to insert pair in-place
    ms.insert(make_pair('b', 25));    
     
    // printing the multiset
    for (auto it = ms.begin(); it != ms.end(); ++it)
        cout << " " << (*it).first << " "
             << (*it).second << endl;
 
    return 0;
}