There are many types of screws available for many different uses. In general, they are categorized by purpose or use in 3 main groups:
They are further categorized by head type (Round, Flat, Oval, Hex, etc.) & drive (Socket or Robertson, Hex, Slotted, Cross or Philips). Add different materials & finishes, plus special purpose such as Drywall or Decking & the combinations are almost endless.