Understanding "while True"

[RedSkeleton007]

The following program works:

#!/usr/bin/env python3
#MovieList.py

def displayMenu():
    print("COMMAND MENU")
    print("list - List all movies")
    print("add  - Add a movie")
    print("del  - Delete a movie")
    print("exit - Exit program")

def list(movieList):
    i = 1
    for movie in movieList:
        print(str(i) + ". " + movie)
        i += 1
    print()

def add(movieList):
    movie = input("Name: ")
    movieList.append(movie)
    print(movie + " was added.\n")

def delete(movieList):
    number = int(input("Movie Number: "))
    if number < 1 or number > len(movieList):
        print("Invalid movie number.\n")
    else:
        movie = movieList.pop(number-1)#movie numbers on the console may start
        #with 1, but the indexes for the movies in the movieList start with 0.
        #Therefore, (number-1) causes the correct index of the movie that we
        #want to delete to be referenced.
        print(movie + " was deleted successfully.\n")

def main():
    movieList = ["Monty Python and the Holy Grail",
                 "Uncle Bazerko's Violent Adventure",
                 "The Expendables",
                 "Duke Nukem: Fate of Humanity"]
    displayMenu()

    while True:
        command = input("Enter command: ")
        if command.lower() == "list":
            list(movieList)
        elif command.lower() == "add":
            add(movieList)
        elif command.lower() == "del":
            delete(movieList)
        elif command.lower() == "exit":
            break
        else:
            print("Not a valid command. Please try again.\n")

    print("Bye!")

if __name__ == "__main__":
    main()

However, I don't quite understand line 41. While what is true? Is the condition simply set to false once we have officially exited the program on line 54?