C++ Why I don't need brackets for loop and if statement

I am really new in coding and I just want to know why I don't need brackets after my second for loop and after my if statement like my 1st example. Second example made more sense to me but was just wondering.

int num[10], min;
for (int i = 0; i < 10; i++) {
    cout << "enter 10 numbers" << endl;
    cin >> num[i];
}

min = num[0];
for (int i = 0; i < 10; i++) 
        if (num[i] < min) 
            min = num[i];


cout << "The smallest number is : " << min;

system("pause");
return 0;





int num[10], min;
for (int i = 0; i < 10; i++) {
    cout << "enter 10 numbers" << endl;
    cin >> num[i];
}

min = num[0];
for (int i = 0; i < 10; i++) {
    if (num[i] < min) {
        min = num[i];
    }
}


cout << "The smallest number is : " << min;

system("pause");
return 0;