two step is an artificial lower RPM limit than the phyiscal hard rpm Limit. 2 step is usually acheived by cutting gasoline and not ignition. 2 steps are usually used in cars with auto transmission.
ALS system are highly configurable in when the ignition cut takes place the amount of fuel and add DBW and it also controls what % the TB stays open. Unlike a 2 step, ALS is controlling the combustion process to take place when the exhaust valve is open allowing the combustion energy to spin the turbo instead of pushing the pistons down.
They are not the same. They are only related in what they control.