How many types of engine do we have?

There are several types of engines, including:

1. Internal Combustion Engines (ICE): These engines burn fuel internally to produce mechanical energy. They can be further classified into:
- Gasoline engines: Used in most cars and motorcycles.
- Diesel engines: Commonly found in trucks, buses, and some cars.
- Rotary engines: Used in some sports cars and aircraft.

2. Electric Motors: These engines convert electrical energy into mechanical energy. They are commonly used in electric vehicles and appliances.

3. Steam Engines: These engines use steam to generate mechanical energy. They were widely used in the past but are now less common.

4. Gas Turbines: These engines use combustion gases to drive a turbine, which generates mechanical energy. They are commonly used in aircraft and power plants.

5. Jet Engines: These engines are a type of gas turbine specifically designed for aircraft propulsion.

6. Rocket Engines: These engines work by expelling high-speed exhaust gases to generate thrust. They are used in space exploration and rocket propulsion.

These are some of the main types of engines, but there may be other specialized or less common types as well.