Answer:
To understand this first you need to know what a byte is. A byte is a set of 8 electrical circuits that can be off or on. There are 256 possible combinations of off and on circuits in a byte which correspond with the 256 ASCII code set(Kind of a more advanced version of Morse code). Each byte then is one letter or number or other special code such as tab or enter or escape or etc ...
Kb stands for Kilo byte meaning 1 thousand bytes
Mb stands for Mega byte meaning 1 million bytes
GB stands for Giga byte meaning 1 billion bytes
Tb st
ands for Tera byte meaning 1 trillion bytes