Engine has 2 spool's with each spool having turbine and compression sections..
Engine is brought up to minimum speed by a pneumatic motor attached to gearbox driving the 2nd spool.
Fuel is sprayed onto an ignition source between the compressor and turbine sections.
The acceleration of the 2nd spool creates more pressure between it and the first spool.
The first spool is connected to the fan that produces most of the thrust.
As you increase the fuel, pressure and airflow (thrust) are a result.
Really need to know what level of detail you are looking for but this is basically any dual spool turbine engine. Do you wish any more detail?