What is Order Book

An order book is a real-time, electronically maintained list of all pending buy (bid) and sell (ask) orders for a cryptocurrency trading pair, organised by price level. Order books are the foundational price discovery mechanism of all centralised exchanges — the engine that matches buyers with sellers to determine market prices. ORDER BOOK STRUCTURE Bids (Buy Orders): All pending orders to buy at specified prices, sorted from highest price (best bid) to lowest. The highest bid is called the "best bid" or "bid price." Asks (Sell Orders): All pending orders to sell at specified prices, sorted from lowest price (best ask) to highest. The lowest ask is called the "best ask" or "ask price." Bid-Ask Spread: The difference between the best bid and the best ask — the cost of immediately executing a trade. Tighter spreads indicate more liquid markets. KEY ORDER TYPES Market Order: Executes immediately at the best available price. Guaranteed execution, no price certainty. Takes liquidity from the order book. Limit Order: Placed at a specific price. Only executes when the market reaches that price. Adds liquidity to the book — often earns maker rebates. Stop-Limit Order: Triggers a limit order when a specified stop price is reached. Stop-Market: Triggers a market order at the stop price. Iceberg Order: Large order displayed in small visible increments to avoid market impact. READING ORDER BOOK DEPTH The depth chart (or market depth chart) visualises cumulative buy and sell orders at each price level. Thick buy walls (large aggregated bid volume at a price level) provide support — large buyers willing to absorb selling. Thick sell walls (large aggregated ask volume) provide resistance — must be consumed before price advances. Walls can be genuine institutional orders or "spoofed" orders placed and cancelled to manipulate perception. ORDER BOOK VS AMM Centralised exchanges and dYdX use order books for price discovery. Decentralised AMMs (Uniswap, Curve) use mathematical formulas instead of order books. Order books offer tighter spreads for large trades but require active market makers. AMMs provide always-available liquidity at any size but with price impact.

Terms in addition to the Order Book

Blockchain

A blockchain is a subset of a distributed database. The Bitcoin inventors originally prototyped the system in 2008. This modern database is made up of separate blocks that are connected together in a chronological chain. Blockchains may be used to store a wide range of data types. It has mostly been utilized as a public ledger for bitcoin transactions to date. A peer-to-peer network comprised of independent nodes uses a consensus process to ensure the blockchain's security and legitimacy. Each node in the network keeps a public and immutable copy of the data.

2 Factor Authentication (2FA)

2 Factor Authentication is a security measure with two layers. It is used by the majority of cryptocurrency exchanges. To log in, you must provide not only a password, but also a code obtained, for example, from the Google authenticator.

Airdrop

An airdrop is a method of distributing coins. End users can typically obtain coins for free or in exchange for doing a small task, such as subscribing to a newsletter, sending a tweet, or inviting others via a personal affiliate link. Cryptocurrency airdrops — the act of depositing cryptocurrency into public crypto wallets — are utilized as a marketing, liquidity creation, and network bootstrapping technique for many different types of blockchain initiatives.

Altcoin

Altcoin - "alternative coin" - is any kind of digital currency other than Bitcoin. Since the launch of Bitcoin, the world's first digital currency, many altcoins (as well as supporting blockchains) have been created. Altcoin digital currencies share many similarities to Bitcoin, but consistently and have significant differences. There are about 20,000 altcoins, and this number is expected to grow significantly in the coming years. Altcoins often develop Bitcoin features. Ethereum, currently the most widely used blockchain, supports digital contracts and separate applications where Bitcoin does not. Altcoins are also often created to cater to the needs of different users. The Litecoin blockchain, for example, can process payments quarterly for the duration of Bitcoin.

Cold Storage

Cold storage is the way to store cryptocurrency offline. The word refers to the use of offline wallets that are not connected to the internet. Cold storage is the most secure way to keep cryptocurrencies since an offline currency becomes less likely to be hacked and stolen. Paper wallets, printed renditions of private keys, and offline hardware and software wallets are all examples of cold storage.