Address

A bitcoin address is a string of characters that represents a wallet that can send and receive cryptocurrency. It is akin to a real-life address, email or website. Every address is unique and denotes the location of a wallet on the blockchain.

Air gap

An isolated computer or network which has no network interfaces connected to other networks, with a physical (or conceptual) air gap (not connected to the Internet).

Algorithm

In mathematics and computer science, an algorithm is a finite sequence of well-defined, computer-implementable instructions, typically to solve a class of problems or to perform a computation. Algorithms are always unambiguous and are used as specifications for performing calculations, data processing, automated reasoning, and other tasks.

Altcoin

Altcoins are cryptocurrencies other than Bitcoin. The majority of altcoins are forks of Bitcoin with small uninteresting changes. This page categorises different ways altcoins have modified Bitcoin. Many people prefer the term "shitcoin" to clearly distinguish all these altcoins from Bitcoin. This term has even been used in US Congress in 2019.

Application Programming Interface (API)

An application programming interface (API) is a computing interface that defines interactions between multiple software applications or mixed hardware-software intermediaries. It defines the kinds of calls or requests that can be made, how to make them, the data formats that should be used, the conventions to follow, etc. It can also provide extension mechanisms so that users can extend existing functionality in various ways and to varying degrees. An API can be entirely custom, specific to a component, or designed based on an industry-standard to ensure interoperability.

Application Specific Integrated Circuit (ASIC)

An application-specific integrated circuit (abbreviated as ASIC) is an integrated circuit (IC) customized for a particular use, rather than intended for general-purpose use. In Bitcoin mining hardware, ASICs were the next step of development after CPUs, GPUs and FPGAs. Capable of easily outperforming the aforementioned platforms for Bitcoin mining in both speed and efficiency, all Bitcoin mining hardware that is practical in use will make use of one or more Bitcoin (SHA256d) ASICs. Note that Bitcoin ASIC chips generally can only be used for Bitcoin mining. While there are rare exceptions - for example chips that mine both Bitcoin and scrypt - this is often because the chip package effectively has two ASICs: one for Bitcoin and one for scrypt. The ASIC chip of choice determines, in large part, the cost and efficiency of a given miner, as ASIC development and manufacture are very expensive processes, and the ASIC chips themselves are often the components that require the most power on a Bitcoin miner. While there are many Bitcoin mining hardware manufacturers, some of these should be seen as systems integrators - using the ASIC chips manufactured by other parties, and combining them with other electronic components on a board to form the Bitcoin mining hardware.

ASIC Miner

An ASIC Bitcoin miner is designed exclusively for the purpose of mining bitcoin. Though significantly more expensive to purchase, they are far more powerful (higher hash rate) and electricity-efficient than CPUs and GPUs (graphics cards) – used for mining in the early days of bitcoin – and even FPGAs (field programmable gate arrays), which were, in 2011, the most efficient option. According to Mike Murray, creator of The Geek Pub, a $2500 ASIC miner is as powerful as 400 GPUs, or 12,000 CPUs, which would cost $18 million. For reference, as of February 2018, the Bitmain Antminer S9 possessed the highest available hashrate at ~14 TH/s, with an efficiency of ~0.1 Joule per GH/s, and cost $3200 on Amazon, not including the power supply. ASIC for bitcoin mining hardware Mining is now so competitive, and the difficulty rate so high, that attempting to do so without an ASIC is unprofitable. Because ASIC mining hardware is so expensive, ASIC for bitcoin mining is done by companies in thermally-regulated data-centers with access to low-cost electricity. Many of these companies lease part of their mining power as a service.

Atomic Swap

Atomic swaps are a mechanism where one cryptocurrency can be exchanged directly for another cryptocurrency, without the need for a trusted third party such as an exchange.

Bit

Bit is a common unit used to designate a sub-unit of a bitcoin - 1,000,000 bits is equal to 1 bitcoin (BTC).

Bitcoin

Bitcoin is a decentralized digital currency created by an unknown person or group of people under the name Satoshi Nakamoto and released as open-source software in 2009. Bitcoin has no central issuer... instead, the peer-to-peer network regulates Bitcoins, transactions and issuance according to consensus in network software. These transactions are verified by network nodes through the use of cryptography and recorded in a public distributed ledger called a blockchain.