Anyone who has ever used a computer has heard the terms, megabyte and gigabyte. And approximately 95% of people do not know what those terms means. And approximately 100% of the statistics used in this blog are fictitious.
To understand gigas, megas and all the other 'as' you need to have an understanding of the smallest unit of information, the bit.
Bit is a contraction of binary digit. Bits are represented by 1s and 0s (or on and off). Without getting into binary just remember the following: there are 8 bits in a byte. I will explain the reasoning behind this in a future blog on binary!
Now, bytes are the smallest unit of measurement that the operating system (Windows, Mac OS, etc) can acknowledge as a unit of storage. A byte can be a single letter, number or character. If you were to create a text document (using notepad) put only the letter 'a' in it, save it and then check the properties of the document you would see that the document you made is only 1 byte in size.
Next we talk about the kilobyte (KB) which is a little harder concept to grasp. If someone says to you, "Kilobyte means there are 1000 bytes in a kilobyte." Karate chop them in the throat, they're wrong. Remember computers are based on a binary system. Binary is based off of powers of 2, therefore 2 ^ 10 = 1024. Have you ever noticed when you go to the store to buy RAM (Random Access Memory) you can only buy sticks in 256, 512, 1024 Megabyes? It's the same reason, although now people are usually getting 1GB 2GB or 4GB sticks.
The rest is quite simple, a megabyte (MB) is 1024 kilobytes. A gigabyte (GB) is 1024 megabytes and a terabyte (TB) is 1024 gigabytes.
Fun fact: A terabyte can hold 1,099,511,627,776 characters.