Binary Digit (Bit)

A binary digit, or bit, is the smallest unit of data in computing.
It can have only two possible values:

• 0
• 1

These values represent concepts like off/on, false/true, or low/high voltage in digital circuits.

Why Bits Matter

A single bit is simple, but combining many bits allows computers to represent:

• Numbers
• Text
• Images
• Audio
• Any digital information

Decimal vs Binary Examples

Number of Values per Bit Count

• 1 bit → 2 values
• 2 bits → 4 values
• 3 bits → 8 values
• 8 bits → 256 values (one byte)

Key Facts

• A bit is the fundamental building block of digital data.
• 8 bits = 1 byte.
• Computers use binary because it is simple, reliable, and easy to implement in hardware.
• Binary is also called the base‑2 numeral system.

Example Conversion

Binary number: 11001₂ Decimal value: 1·2⁴ + 1·2³ + 0·2² + 0·2¹ + 1·2⁰ = 25