Lungo is a type of coffee that is made by brewing a lot of water through a little bit of coffee. It's called "lungo" because it means "long" in Italian, and the process takes a little longer than making regular coffee.
Basically, when you make lungo, you first put some coffee grounds into a special pod or capsule. Then you put the pod into a machine that heats up water and pumps it through the coffee grounds at high pressure. This makes the water go through the coffee really slowly, so that more flavor is extracted from the beans.
The result is a cup of coffee that is stronger and more intense than regular coffee. However, because more water is used to make lungo, it's also a little bit lighter than espresso, which is even stronger.
So, to sum up: Lungo is like coffee's big brother. It's made by brewing a lot of water through a little bit of coffee, which takes more time than regular coffee. The result is a stronger and more intense flavor, but still lighter than espresso.