A byte is a basic unit of digital information that typically consists of eight bits. Each bit is a single binary value of zero or one, so a byte can represent 256 different combinations. In practice, bytes are used to store small values like characters, parts of images, or segments of larger numbers. Most computer architectures and operating systems are optimized around bytes as the smallest addressable unit of memory. Higher level sizes like kilobytes, megabytes, and gigabytes are all defined in terms of bytes. When you see file sizes in a file system or storage usage in dashboards, those numbers are ultimately counting how many bytes are being used.
why it matters
Understanding bytes helps you reason about memory usage, network traffic, and performance. When sending data over the network as packets, systems often limit the number of bytes per packet or per second. Data formats such as text encodings, images, or video streams specify how they map information onto sequences of bytes. Bugs involving mismatched sizes, such as reading too many or too few bytes from a stream, can lead to crashes or security issues. When working with AI on performance or low level tasks, being aware of how many bytes a structure uses can help you ask better questions and interpret results more accurately.