DeFi & stablecoins
CEX and DEX: Two Ways to Exchange Crypto Assets
A centralized platform manages a service and often the storage of assets. A decentralized exchange relies on programs and a wallet, with its own set of risks.
Ethan BrooksEditorial pen name
Two exchange models
A CEX is a centralized exchange platform: a company organizes the service, manages accounts, and sets access conditions. It often stores crypto assets for its clients. The visible balance then corresponds to an internal accounting system; each exchange between clients does not necessarily trigger a transaction on the blockchain.
02How it works+
The user can deposit funds, place orders, and request a withdrawal. These functions depend on the markets offered and the operator's rules. A simple interface does not eliminate the risk associated with the company: service availability, security, storage, and ability to honor withdrawals remain distinct elements from the used blockchain.
Custody and execution
03Key points to remember+
A DEX is an exchange mechanism based on programs deployed on a blockchain. The user interacts with a wallet for which they control the permissions. Some DEXs use order books; others work with common reserves, called liquidity pools. In the latter model, the exchange is made against the assets available in the pool.
For example, exchanging one token for another can modify their proportion and therefore the proposed price. The depth of liquidity influences the result: a significant operation compared to the reserves can move the price. The exchange fees and those of the network are added according to the functioning of the concerned protocol.
The absence of centralized storage does not make an operation risk-free. A contract can contain a flaw; an interface can be trapped; a fake token can take over a known symbol. Certain permissions also allow a program to move tokens later. Intermediaries do not all disappear: sites, operators, and infrastructures can still intervene. Finally, technical access to a protocol does not exempt from the rules applicable to its user. To distinguish between CEX and DEX, the useful question is therefore twofold: who controls the funds, and what rules execute the exchange that one wants to carry out?
Reconstruct the stages of a trade
On a centralised platform, a trade can be recorded in the service's internal accounts without immediately generating a blockchain transaction. A withdrawal is then a separate operation governed by the platform's conditions and the selected network. With a decentralised exchange, users generally interact with contracts through their wallet. This difference changes how an operation is followed and who can authorise movements at each stage. An exchange confirmation and a completed transfer to an external address are consequently different pieces of information.
Consider a fictional trade between two tokens. The indicative price before confirmation can differ from the final result if conditions change or the order uses a significant share of available reserves. Service fees, network fees and the price difference are separate components of cost. Comparing interfaces only through the number displayed beside a button may therefore fail to describe the amount ultimately received. A meaningful comparison considers the same quantity and includes the relevant steps in each trading route.
Compare responsibilities separately
Access to a service, asset custody and transaction execution require separate examination. A public protocol may be used through an interface operated by a company. A centralised platform may offer features connected to external wallets. The CEX and DEX categories provide an initial reference, but do not answer every practical question. Supported assets, available networks, withdrawal rules and requested permissions explain the actual arrangement in more detail. A label is useful when it leads to these distinctions, rather than replacing them.