the purpose of struct in c++ code example

Example 1: what is a struct in c++

struct Person
{
    char name[50];
    int age;
    float salary;
};

Example 2: c++ struct

#include<iostream>
#include<string>
using namespace std;
struct student
{
  char name [20];
int age;
float marks;
};
int main()
{
student s;
cout<<"enter student name : "<<endl;
cin>>s.name;
cout<<"enter age : "<<endl;
cin>>s.age;
cout<<"enter marks : "<<endl;
cin>>s.marks;
cout<<"***********************"<<endl;
cout<<"name : "<<s.name<<endl;
cout<<"age : "<<s.age<<endl;
cout<<"marks : "<<s.marks<<endl;
return 0;
}