What is the difference between ristretto,ristretto and espresso

What is ristretto,ristretto and espresso? is there any difference?

Ristretto can be simply understood as a concentrated version of espresso.

Before the emergence of the commercial coffee machine commonly used today, it used the kind of coffee machine with a handle. When you want extract coffee alone, you pull the lever down, and then the coffee will flow out. This manual coffee machine will shorten the coffee time to a great extent. This is the ristretto in the original sense, because the taste of hot water is not so strong after the coffee time is shortened. It won't be so bitter.

Now people usually refer to ristretto: do not add the standard amount of espresso, the extraction time is shortened. Generally, the amount of double esspresso is 60ml (2oz), but double ristretto is relatively less, usually 45ml (1.5oz).