How can a user input words?

int blabla;
cout << "This is a random line";
cin >> blabla;

#include <iostream>
#include <Windows.h>

using namespace std;

int main()
{
	char passwd[50];
		cin >> passwd;
	if(passwd == "kana"){
		cout << "Access Granted";
	}else{
		cout << "Access Denied";
	}
}

if(!strcmp(passwd, "kana") // strcmp returns 0 if both strings are the same
{
//code
}

if(std::string(passwd).Compare("kana"))
{
}

#include <iostream>
#include <string.h>
using namespace std;

int main()
{
	string passwd;
		cin >> passwd;
	if(passwd == "kana"){
		cout << "Access Granted";
	}else{
		cout << "Access Denied";
	}
}

#include <iostream>
#include <string>

using namespace std;

int main(){
	string acc, pw;
	cout << "Username: \n";
	cin >> acc;
	cout << "Password: \n";
	cin >> pw;
	if(acc == "MPGH"){
		cout << "Username correct\n\n";
	}
	else if(acc != "MPGH"){
		cout << "Username incorrect\n\n";
	}

	if(pw == "cplusplus"){
		cout << "Password correct\n\n";
	}
	else if(pw != "cplusplus"){
		cout << "Password incorrect\n\n";
	}
	if(acc != "MPGH" && pw != "cplusplus"){
		cout << "Username or/and password incorrect, are you sure you got the valid info?" << endl << "contact me for the password and username\n" << endl;
	}
	else if(acc == "MPGH" && pw == "cplusplus"){
		cout << "Information correct. Press any key to see your code." << endl;
		system("pause");
		cout << endl;
		cout << "Code : gHahwsejGKfndfj6893860339gDhbJeGhtdhzxvnG" << endl << "paste this on the forum\n\n";
	}
	system("pause");

}

#include<iostream>
#include<cstdlib>// to add Pauses, if u don't want them then erase em.
#include<string>
#include<windows.h>//I think u need this to erase everyting on the screen. //don't remember

using namespace std; // so u can just write cout instead of std::cout

int main()
{
   string username = "Guest"; // declare a string variable and initialize it.
   string password = "MPGH";
   string userInput1;
   string userInput2;

   int security;

// a string variable holds letters. Which in this case it's what you want

   cout << "username: ";
   cin >> userInput1;

   system("CLS"); // erases everything on the screen. 

   cout << "Password: ";
   cin >> userInput2;

   if(userInput1 == username)
   {
       security = 5;
       
       if(userInput 2 == password)
       {
       security = security + 5;


       }

   }
   else 
   {
   security = 0;

   }
   
   if(security == 10)
   {
      cout << "Welcome guest!\n\n";

   }
   if(security == 5)
   {
        cout << "incorrect password or username. Shutting down.\n";
        system("PAUSE");
        return 0;
   }
   if(security == 0)
   {
        cout << "error Shutting down\n\n";
        
        system("PAUSE");
        return 0;


   }

 system("PAUSE");
 return 0;
}

#include < blah blah my hearder>

using namespace std;


int main()

{
                      cout << "Hello my first message in output";
// output ( message )

			cin >> inicial >> final >> razao;

// input ( when the person enter something into the screen)


}