While all three are units of memory storage on a computer, a kilobyte (KB) is smaller than a megabyte (MB) and a MB is smaller than a gigabyte (GB). There are 1,024 bytes in 1 KB, 1,024 KB in 1 MB and 1,024 MB in 1 GB.
The files stored on a computer are measured in bytes. Each byte consists of 8 bits, and each bit is either a one or a zero. The 8 bytes together describe a character, which is a number, letter or symbol that the computer can interpret and display on the monitor. A single byte can store one character, which means a single kilobyte, or 1,024 bytes, can store 1,024 characters.