Bits and Bytes: A Basic Introduction

Bits and bytes are measurements of data, but they differ in their size and what they measure. Understanding what these terms are will help you understand how your computer stores information and how your Internet connection speed effects you. One way to tell them apart is the case in which they are written. When abbreviating bits and bytes, a "b" (small case) is a bit, and "B" (upper case) is a byte, therefore, "kb" is kilobit and "KB" is kilobyte (note: the case of the letters before the b are insignificant).

A bit (b) is the smallest measurement of data that can be stored on computers or transferred by Internet services. Bits represent information with a binary coding system made up of only 1's and 0's (bi means two, i.e., two numbers). When bits are arranged and stored in sequences of 1's and 0's, they are translated by computer programming into words, pictures, and other data.

Usually, when you hear the term "bits", they are measuring transfer rate, or how much information can be transferred in a certain amount of time. Internet connection speeds are measured this way, for example, "bps" is bits per second, the amount of bits that can be downloaded or transferred in a second. Since bits are so small, most connection speeds are measured in thousands of bits per second.

When measuring transfer rate for Internet connections, 1 kilobit (kb) = 1000 bits, 1 megabit (mb) = 1000 kilobits. Say you connect with dial-up at 34.4 kbps. That means 34.4 kilobits or 34400 bits can be downloaded per second to your computer. Say you connect with cable at 6 "megs" aka mbps. You can download 6 megabits, or 6000 kilobits, or 6,000,000 bits per second.

A byte (B) is 8 bits strung together. Remember, bits store information based on a binary system and are arranged in sequences. These sequences are in sets of 8 and called bytes. It takes many bytes sequenced together to create documents, images, programs, and commands for your computer. When measuring sizes of files, programs, and capacities of drives, you use bytes. Like bits, byte are often noted in larger quantities, like kilobytes, megabytes (megs), and gigabytes (gigs).

Many people assume a kilobyte is 1000 bytes, etc., but this is not true. When describing capacity (size or storage size of computer elements), bytes are measured by the same binary system that code bits. Therefore, "kilo" = 1,024 (or, 2^10) instead of 1000. A kilobyte (KB) is 1,024 bytes, and a megabyte (MB) is 1,024 kilobytes. A gigabyte (GB) is 1,024 megabytes.

A Microsoft Word document is usually about 30 KB in size. An picture, like clip art is typically about 100 KB, and photos are often much larger. A CD typically has a 700 MB (or 716,800 KB) storage capacity. You can buy computers with a hard drive (main storage unit) capacity of 500 gig (or 524,288,000 KB).

Don't forget, 1 byte is 8 bits. An Internet connection (like transfer rates or download speeds) is measured in bits, and 1 kilobit is 1,000 bits. Storage capacity (like disk space and file sizes), it is measured in bytes, and 1 kilobyte is 1,024 bytes.