Although the gigabyte serves as the bare minimum of storage for devices, it isn’t the smallest unit available. Below the gigabyte are the megabyte, kilobyte, byte, and bit. A bit is the smallest basic unit seen by a computer, being a simple binary calculation. There are eight bits in a byte, and 1,024 bytes in a kilobyte.
The sizes grow exponentially, but the gigabyte is a happy medium for most purposes.