Most of us have heard of Bytes, Megabytes and Gigabytes, some even know about Terrabytes, but what about a Zettabyte? Well over the next few years, it looks like a term that is likely to become as popular as a Gigabyte, but to put this into perspective we need to look a little bit closer at these terms. There is a thousand Megabytes in a Gigabyte and then a thousand Gigabytes in a Terrabyte and so one until reach Zettabyte, which three more down the line past the Petabyte and then the Exabyte! The same formula is applied, so each step is multiplied by a thousand. To put it into perspective there is a cool info graphic that explains it far better than I could!
Source [Device Mag]