"64 KB" refers to a unit of digital information storage that equals 64 kilobytes. A kilobyte is made up of 1,024 bytes, so 64 KB is 65,536 bytes. This amount of data is relatively small by today's standards, often used to describe the memory capacity of early computers and devices. In the context of computing, 64 KB was significant during the 1980s and 1990s, as many early personal computers, like the IBM PC, had memory limitations around this size. Today, modern devices typically have gigabytes (GB) or terabytes (TB) of storage, making 64 KB seem minimal.