English: An animation of a turbofan engine, made in Blender, labels made in Inkscape.

This is a 2-spool, high-bypass turbofan. The high pressure spool (yellow, B) acts as a gas turbine generating a powerful jet of exhaust gas which drives the rotation of the low pressure spool (turquoise, A). The low pressure spool rotation aids compression for the turbine and rotates the fan, the fan provides additional thrust. The two spools, yellow and turquoise, spin at different speeds - the high pressure spool rotates significantly faster than the low pressure spool. High-bypass refers to the ratio of air volume which goes through the turbine compared to the volume which goes through only the fan - far more air travels through the fan than the turbine in a high-bypass engine. High-bypass turbofan engines provide good thrust at the higher sub-sonic speeds and low-bypass models can be used up to approximately Mach 1.6. At the highest speeds turbojet engines are more effective while turboprop engines are more effective at much slower speeds.
1. Nacelle
2. Fan
3. Low pressure compressor
4. High pressure compressor
5. Combustion chamber
6. High pressure turbine
7. Low pressure turbine
8. Core nozzle

9. Fan nozzle