The "while" loop is a function built-in C language which allows you to loop certain piece of code until the criteria is met instead of retyping the code all over again.
For example, this is C# thought (similar concept, different syntax):
string userInput = "0"; - define the variable to something else other than 'end' so the while loop executes the first time!
while(userInput != "end")
{
Console.WriteLine("The look will continue to print this text unless you type the word 'end' at the prompt!");
Console.WriteLine("Enter text: ");
userInput = Console.ReadLine();
}