bit:The smallest storage unit of a computer
byte:Common computer storage unit
word:Computer natural storage unit
bit:A binary number.zero or one.
byte:1 byte equal to 8 bit .show 0-255 integer
word:1 word lengh equal 8bit or 16bit or 32bit.The bigger the better.
原文：https://www.cnblogs.com/enomothem/p/11571661.html