Machine vs. Engine

What is the difference between Machine and Engine?

Machine is a device that directs and controls energy, often in the form of movement or electricity, to produce a certain effect. It has many parts, each with a definite functions, together performing a particular task. For example, a car is a machine because it has many parts that together performing a particular task.

Engine is a component with moving parts that converts energy into motion. Engine is the heart of the machine, due to which the machine works. For example, a car engine converts energy from fuel to motion. Engine is one type of machine. It does useful work only when it is converted to a machine.

All engines can be called as machines, but not all machines can be called as engines.

In computing context, machine is a computer/electronics devices while engine is a hardware or software system responsible for a specific task. For example, a modem (machine) needs a baseband processor (engine).

Reference:

[1] https://www.quora.com/What-is-the-difference-between-an-engine-and-machine

[2] http://wikidiff.com/engine/machine