What is Binary?
Binary is the base-2 number system, using only the digits 0 and 1. It is the native number system of all digital computers because transistors have two states (on/off), which map directly to the binary digits 1 and 0. Every number, character, image, and instruction in a computer is ultimately represented as a sequence of binary digits (bits).
In binary, each digit position represents a power of 2, starting from 2^0 = 1 on the right. The binary number 1011 means 1×8 + 0×4 + 1×2 + 1×1 = 11 in decimal. This positional system is identical to the familiar decimal (base-10) system, just with a smaller base.
A single binary digit is called a bit. Eight bits form a byte, which can represent 256 different values (0–255). Bytes are the standard unit for measuring file sizes, memory, and network bandwidth. Common groupings include the nibble (4 bits, one hexadecimal digit), the word (typically 16 or 32 bits depending on architecture), and the double word (32 bits).
Binary is foundational to understanding how computers work. File permissions on Unix systems use octal notation, which maps cleanly to groups of three binary bits. Bitwise operations (AND, OR, XOR, NOT, shifts) operate directly on binary representations and are used in cryptography, networking, graphics, and low-level programming.
Hexadecimal (base-16) is a compact shorthand for binary: one hex digit represents exactly four binary digits (a nibble). Programmers read hex values instead of long binary strings for memory addresses, color codes, and byte sequences.
Use the Number Base Converter to convert between binary, octal, decimal, and hexadecimal instantly, including grouped nibble and byte formats for readability.