What does the "new" keyword do and how to use it?

The new keyword makes a new instance of a class.

Classes are very confusing for beginners. Even myself was extremely confused when I was learning this topic. However, I'll try to make it easy-to-understand by using examples.

Think of a class as a cookie cutter. A cookie cutter is basically a blueprint; when you are making cookies, you use the cookie cutter to make cookies, you don't eat the cookie cutter itself. In this case, the cookie cutter makes "instances" of itself.

When you use (eat) a cookie, you don't eat the cookie cutter itself; you use that to make the cookies. You eat the "instances" of the cookie cutter (the cookies) instead.

Another example: You have a Car class. Remember, a class is just a blueprint of something, in this case our class is modeling what a car would be. We can use this class to make instances of itself, basically saying that "you use the model to make the car". I know it's confusing...

Remember that you are free to make as many instances as you want

Example in code:

public class Car {
  public static void Car(name, color) {
    this.speed = 0;
    this.brand = brand;
    this.color = color;
  }
  public void pressTheGas() {
    this.speed += 10;
  }
  public void slowDown() {
    this.speed -= 10;
  }
  public int getSpeed() {
    return this.speed;
  }
}

// Over here we're going to make new instancea of Car! Remember, this is
// "Making a cookie using the cookie cutter" where the class is the cutter and the new
// instance is the cookie.

Car honda = new Car("Honda", "Black");
Car jeep = new Car("Jeep", "Blue");
Car tesla = new Car("Tesla", "Red");

I hope this helps you out!

~Alex