What is the difference between a CEX and DEX transaction?

The DEX transaction takes place via a DEX aggregator who finds the optimal route to execute the swap for the best price via one or more liquidity (AMM) pools listed on one or multiple connected DEXs. The user can set a slippage tolerance percentage, and if the swap can be executed within this tolerance, the transaction will be executed immediately in a single-hash transaction. If not, the order will fail (be rejected). 

The CEX transaction consists of 3 (done-for-you) steps: a deposit of the source token to the exchange, the actual swap/trade via a market order, and a withdrawal of the destination token to the user’s wallet. This process makes cross-chain transactions possible as long as CEXs support multiple token formats. The user has to pay the deposit gas fee, while the RX protocol deducts the platform fee and the CEX withdrawal fee from the number of destination tokens. The shown Quote (expected number of to-be-received destination tokens) is after the deduction of the CEX withdrawal fee. As the actual order is being executed as a market order, the slippage tolerance percentage and Minimum Received don’t apply for CEX transactions. Also, the CEX transaction processing time is a little longer in comparison to a DEX transaction.