By Body Shape
Acoustic guitars come in various body shapes, as well as different sizes. See Guitar Body Shapes
Not all guitar manufacturers make all body shapes, or in all sizes. Also, some body shapes or sizes could be exclusive to a particular manufacturer. Typically a smaller body size does not have the volume or tonal richness as larger body guitars. Choosing a size is based on personal preference to match the physical size of the player, and/or for sound quality or portability. Matching the right string gauge and string material also will affect overall sound quality. See String Buying Guide.