Fun fact: If you've typed in a fairly large number in the left box on the last page, you may have seen the message 'Too large to process!' in the right box. That's a good example of not having enough bits to represent the datum you want and also demonstrates the power of binary.
It also shows how ineffective it is to describe the amount of memory using bits. This is where bytes come in. A byte is defined as eight bits. Bytes can't represent too many things - only 256, really. Fortunately, they can represent one single simple Roman letter (we'll - hopefully - find out why in a later lesson).
To further pack our bits into neater packages, we can use kilobytes, megabytes, gigabytes and terabytes. Each prefix is 1024 (210) times the previous one: A kilobyte is 1024 bytes, a megabyte is 1024 kilobytes (1,048,576 bytes), a gigabyte is 1024 megabytes (1,073,741,824 bytes), and so on. See how fast the numbers grow? That's the power of binary!
If you're the lazy type, you can always use abbreviations. Bits are represented by a lowercase 'b', bytes by an uppercase 'B', kilobytes by KB, megabytes by MB, gigabytes by GB and terabytes by TB. (Note that the 'b' abbreviation for bytes isn't too common. It's advisable to avoid using it in a non-technical context lest the reader should confuse it with 'B'.)