Are 808s and bass instruments the same? What's the difference between the two and can they be use interchangeably?
The primary differences between beatmakers and music producers has to do with what kind of music is being made, in addition to a few subcultural differences.
Garageband does have autotune and pitch correction by default, however, third party plug-ins such as Melodyne or MAutoPitch are better options.
Due to the technological advancements of plug-ins, analog to digital converters, and VST technology, you can produce music on a laptop, but there are a few reasons why you wouldn't want to.