N1 fan blades driven by exhaust gasses of last blade sets. Suck.

N1 is the first spool in the engine, for airliners this is the fan in the front. N2 is the core compressor spool. Some Rolls Royce engines have a second core spool, known as N3. More specifically, N1 and N2 are the rotational speeds of those engine sections expressed as a percentage of a nominal value. Think of it as being analgous to the RPM of a piston engine, only expressed as a percentage rather than the actual rate of rotation. The first spool is also known as the low pressure compressor (LP) and the second spool is known as the high pressure compressor (HP).

Compressor section part of outer shaft assembly. Squeeze.
Combuster Compressor hot section fuel air mix and ignition. Bang!
Turbine N2 and N1 inner shaft drives large front n1 fan blades for bypass air. Blow