The term 'prefix with byte' refers to a set of four prefixes used in computing to denote the size of a unit of data. The prefixes are tera (T), kilo (K), giga (G), and mega (M). Tera is the largest prefix, representing one trillion bytes, while kilo is the smallest, representing one thousand bytes. Giga represents one billion bytes and mega represents one million bytes. These prefixes are used to denote the size of a unit of data, such as a file or memory.