Also known as: Bit, Byte
A bit is the smallest unit of digital information — a single binary digit, either 0 or 1 — and a byte is a group of eight bits.12
Overview
Everything a computer stores or moves is encoded in bits, physically realized as a transistor switched on or off, a charge present or absent, a voltage high or low. Grouping eight bits into a byte gives a convenient chunk that can represent 256 distinct values (0–255) — enough for one character of basic text, one level of a colour channel, or one small integer.
Within a byte each bit carries a place value that doubles from the least significant bit (worth 1) on the right up to the most significant bit (worth 128) on the left, exactly like decimal place value but in base two. Larger quantities are counted in kilobytes, megabytes, gigabytes, and terabytes.
A persistent source of confusion is that data rates are usually quoted in bits per second (the unit of bandwidth) while storage sizes are usually quoted in bytes — so a “100 Mbps” link moves only about 12.5 MB each second.
Counting in bigger units
Because computers address memory in powers of two, the “kilo/mega/giga” prefixes are often used to mean powers of 1024 rather than 1000; standards bodies coined the binary prefixes (KiB, MiB) to make the distinction explicit.
| Unit | Bits | Bytes | Rough scale |
|---|---|---|---|
| Bit | 1 | ⅛ | one 0 or 1 |
| Byte | 8 | 1 | one text character |
| Kilobyte (KB) | 8 × 10³ | 10³ | a short email |
| Megabyte (MB) | 8 × 10⁶ | 10⁶ | a minute of music |
| Gigabyte (GB) | 8 × 10⁹ | 10⁹ | a movie |
| Terabyte (TB) | 8 × 10¹² | 10¹² | a large drive |
Where it fits
Bits and bytes are the common currency of every other hardware idea: memory and storage are sized in bytes, logic gates operate on bits, and a CPU’s word width is a bit count. In SDR terms, the IQ samples GopherTrunk ingests are streams of bytes, and a decoded voice frame is ultimately a precise pattern of bits pulled out of the noise.