Is the Z80 "Game Boy" an 8 or 16 bit processor?

Question

I read a tutorial on creating a Game Boy emulator, I understand that Game Boy uses an 8-bit processor, but I can not understand why Gameboy uses two types of data: bytes (8 bits) and words (16 bits).

If the processor has a capacity of 8 bits, why can I use 16 bits?

Answer 1

The processor and registers have 8 bits, but can store and use 16-bit data by grouping two registers as if they were one 16-bit register. This website contains excellent information on Gameboy equipment.