Bit to Gigabit

A bit is a single binary value (0 or 1); a byte is a group of 8 bits. Bytes are the standard unit for file sizes, memory, and storage. Network speeds are typically quoted in bits per second (Mbps), while file sizes use bytes (MB) — so a 100 Mbps connection downloads 100 megabits, or about 12.5 megabytes, per second.

Networking hardware physically transmits one bit at a time over a wire or radio signal, so bits per second is the natural unit for measuring throughput. The convention predates widespread file-size awareness. When you see "100 Mbps broadband", your actual download speed in MB/s is about 1/8 of that — roughly 12.5 MB/s.

A classical bit is definitively 0 or 1. A qubit can exist in a superposition of both states simultaneously, described by two complex probability amplitudes. When measured, a qubit collapses to 0 or 1 — yielding one classical bit of information. The power of qubits lies in entanglement and interference during computation, not in storing more data per unit. A 100-qubit quantum computer does not store 100 bits more efficiently; it explores 2¹⁰⁰ computational paths in parallel for specific algorithm types like factoring and search.

Information theory, developed by Claude Shannon in 1948, quantifies how much information a message contains. One bit is the amount of information needed to resolve a choice between two equally likely outcomes. This abstraction underpins all digital compression, encryption, and error-correction — from MP3 audio to HTTPS security.

In practice, modern computers cannot address or store a single bit individually — the minimum addressable unit is one byte (8 bits). Trying to store a single bit requires a full byte, with 7 bits unused. Some specialised hardware and bit-packing algorithms can store multiple boolean values per byte, but standard memory hardware works at byte granularity.

1 Gbps (gigabit) broadband delivers up to 125 MB/s, which is more than sufficient for most households. It supports dozens of simultaneous 4K streams, fast game downloads, and video conferencing with headroom to spare. The limiting factor is usually the Wi-Fi router (Wi-Fi 5 maxes out around 400–600 Mbps in practice) or the speed of the remote server you're downloading from.

10 Gbps networking is standard in data centers, server interconnects, and high-performance workstations doing large file transfers (video editing, database backups). It is increasingly available in prosumer home networking equipment. At 10 Gbps, a 1 TB file transfer takes about 13 minutes under ideal conditions.

One terabit equals 1,000 gigabits (SI). Terabit-per-second (Tbps) speeds are used in long-haul fiber optic cables and internet backbone infrastructure. A single transatlantic fiber cable typically carries hundreds of terabits per second across many multiplexed channels.

Wi-Fi 5 (802.11ac) delivers up to 3.5 Gbps theoretical, but typically 400–600 Mbps real-world on a single device. Wi-Fi 6 (802.11ax) reaches 9.6 Gbps theoretical and 600–900 Mbps practical per device, with better multi-device handling via OFDMA. Wi-Fi 6E extends the same technology into the uncongested 6 GHz band, improving real-world speeds to 1–2 Gbps. Wi-Fi 7 (802.11be) pushes the theoretical maximum to 46 Gbps using 320 MHz channels and 4096-QAM, with real-world single-device speeds expected around 2–5 Gbps — the first Wi-Fi standard to reliably exceed gigabit in practice.

Modern data centers handle enormous simultaneous traffic between thousands of servers — cloud computing, video streaming, and AI training all require massive internal bandwidth. 100 Gbps links between switches are now standard; 400 Gbps is increasingly deployed for spine connections. At these speeds, a single link can move 50 GB of data per second, keeping pace with NVMe storage arrays and GPU memory transfer rates.