This section includes home keyboards such as the Casio CTK and MT series, Yamaha PSR and PSS series, and other home keyboards ranging from the most basic of toy keyboards up to devices that blur the line between home keyboards and professional synthesizers.
Home keyboards often have built-in speakers, non-programmable sounds, and lack many of the features and build quality of professional gear. Having or lacking a particular feature does not necessarily make a piece of gear "professional" or "amateur". Some legitimate synthesizers have built-in speakers, and some "toy" keyboards can sound very high-end.
This section also includes professional arranger keyboards because they evolved from home keyboards. The line between high-end home keyboards and professional arrangers is a very blurry one.