How do you compare strings as arguments?

I am trying to write a programm that reads the surname introduce and gives back the info of the student (birthdate, group, etc). The compiler does not recongize the == operator, I guess it doesnt know what to compare, either the address or the value?(I would appriciate an explanation)

I read similar cases and they suggest to use bool operator. As far as I know bool operator just returns true or false(I dont see the way to use it to print the students info)

Also I was considering usind char or using strcmp (srting functions for comparing).

   void find_fam ( struct st student[], int length, string & fam)
    
    {
        for(int i=0; i<length; i++)
            if ( student[i]== fam[i]){
        
        cout << "Student:\n"<< student[i].imia << student[i].otchestvo << student[i].familia << 
student[i].gruppa << student[i].grozhdenia);
                                                             
            }
    }