Bits and bytes are units of measure for digital data. A byte is larger than a bit. An easy way to remember that bytes are a larger unit of measure than bits is that the word byte is larger than the word bit. So, the larger word corresponds to the larger data unit, and the smaller word corresponds to the smaller data unit.
What is a bit?
The word bit is shorthand for binary digits. A bit can represent either a zero or a one. This is based on the fact that electricity can be either on or off. Other signals used on the internet similarly vary between an on and off state as their basic means to transmitting data. You can think of it a little bit like Morse code, which uses dots and dashes to convey information.
A bit is the smallest unit of data that computers work with. In fact, it is the basis for all other data on the internet and individual computers. Since bits are inherently based on one of two states, bits are inherently binary. This fact profoundly shapes digital data in many ways. The essence of it is that a lot of important numbers on computers or the internet are based on powers of 2. This is why you frequently see numbers like 8, 16, 256 and 1024. You will see this underlying principle in many places.
What is a byte?
A byte is a group of 8 bits. It is used to create characters, such as letters, numbers and other characters found on your keyboard. Computers make very long strings of ones and zeros and then break them up into groups of various sizes. All other data is built in this way.
Because bits are binary, and the byte is a unit of 8 bits, it translates to 2 to the 8th power worth of variations. Thus, there are 256 variations of the byte. Different variations get assigned to upper case letters of the alphabet, lower case letters, numbers and other characters.
Kilobyites, Megabytes and More
Most of the time, you will hear the words bits and bytes with prefixes like kilo, mega, giga or tera. So, you will often hear people refer to kilobytes, megabytes, or gigabytes. These prefixes are the same ones used in the metric system, but they don’t actually mean the same thing.
Kilo means thousand (1000). But, when used with digital data, its value is 1024. Mega means million (1,000,000). But, when this same prefix is used with digital data, its value is 1,048,576. The reason for this is that digital data is based on powers of two. So, kilo is 2 to the 10th power and mega is 2 to the 20th power.
In contrast, the metric system is base don powers of 10. Thus, everything gets larger by some power of 10, like 10 times, 100 times, 1000 times, etc. As noted above, the difference here is that all digital data is based on the bit, and the bit is inherently binary. This influences the value of the various prefixes used for measuring digital data.
Gigabytes are 1,024 megabytes or 1,073,741,824 bytes. Because computing power has grown, this has become a common measure of hard drive size. You still typically hear megabytes used for measuring data speed over the internet, or download speed. Sizes beyond that include terabytes, petabyte, and exabytes. Those are really, really big measures and not in common usage, at least not yet, though the word terabytes is being seen a bit more frequently these days.
The abbreviation for megabyte is MB. The abbreviation for megabit is Mb. It may be easy to mix them up, but just remember that the bigger byte uses the big B and the smaller bit uses the small b. This principle will hold true for other abbreviations, like gigabyte (GB) and gigabit (Gb).
Bits and bytes are units of measure for digital data. Digital data is information found on your computer or the internet. Bits are smaller than bytes. Conveniently, the word bit is smaller than the word byte and the abbreviation for bit uses the small (lower case) b, whereas the abbreviation for byte uses the large (upper case) B. If you keep those associations in mind, you shouldn’t mix them up.
Photo by Patrick Lindenberg