The bit is the most fundamental unit of digital information, representing a single binary value of either 0 or 1. Every piece of data stored or transmitted across the internet ultimately consists of bits, from a single text character to high-definition video streams. Eight bits make up one byte, which is why data storage is typically discussed in bytes rather than bits.

The kilobyte (KB) equals 1,024 bytes in binary computing terms and is used to measure small files like text documents, email messages, and thumbnail images. While the term sometimes refers to 1,000 bytes in networking contexts, operating systems consistently use the binary definition. One kilobyte can store roughly half a page of plain text.