These terms are all used to measure amounts of data.Â In terms of web hosting they are relevant for disk storage (quota) and transfer limits (bandwidth). In English we use the same set of prefixes for measurements as well. Kilo refers to thousand. 1,000 (10^3)Â e.g. 1 kilometre = 1,000 metres Mega refers to million. 1,000,000 (10^6)Â e.g. 1 megawatt = 1,000,000 watts Gig refers to billion. 1,000,000,000 (10^9) e.g. 1 Gigawatt = 1,000,000,000 watts Tera refers to trillin. 1,000,000,000,000 (10^12) The smallest measure we use for data is a byte (b) that has the value of either 0 or 1. So when we refer to 1 Gigabyte (GB) we are actually talking about 1 billion bytes of data.Â Because a byte is so small we normally express storage in either Megabytes (MB) or Gigabytes (GB).Â 1GB can also be referenced at 1,000MB. This form of calculation is used for web hosting, however, technically speaking (as geeks would) 1GB is actually 1,024MB.Â For the more technically minded and curious here are the true value calculations. 1 bit = a 1 or 0 (b) 8 bits = 1 byte (B) 1024 bytes = 1 Kilobyte (KB) 1024 Kilobytes = 1 Megabyte (MB) 1024 Megabytes = 1 Gigabyte (GB) 1024 Gigabytes = 1 Terabyte (TB) A bit is represented with a lowercase "b," whereas a byte is represented with an uppercase "b" (B). So Kb is kilobits, and KB is kilobytes. A kilobyte is eight times larger than a kilobit. A kilobyte KB (2^10, 1024) is very close to 10^3, 1000.Â So the common use prefix kilo was most often used.Â It's a very small difference but as the number grows it can add up.Â Now that we know that one kilobyte is actually 1024 bytes, and 1024 of those is (1024 x 1024) 1048576 bytes a true megabyte = 1,048,576 bytes. And finally, one real Gigabyte is really 1,073,741,824 bytes (1024 x 1024 x 1024).