* A byte is the basic unit of data storage in a computer. (This is a simple and accurate definition)
* The file size of this image is about 2 megabytes. (This shows a byte in action)
* The computer's processor can handle billions of bytes per second. (This emphasizes the speed of data processing)
* A byte consists of eight bits, each representing a 0 or 1. (This gives a technical definition)
* The software requires at least 4 gigabytes of RAM to run smoothly. (This shows how bytes are used in software)
The best sentence will depend on the context and what you want to emphasize.