It should be said that it is 8 bits. If expressed in English, 1byte is 8 bits. Generally our PC is 32-bit, which is 4 bytes.

However, it seems to depend on the type of computer, some are 8-bit, some are 4-bit or even 2-bit.

Just ignore that sentence, things keep changing. If you want to master it, look at the composition principles and operating systems

I personally think that foreigners think that 8 bits can represent commonly used letters and symbols, so the bytes are set to 8 bits. If the Chinese designed it, it would probably be 16 bits.