A Transaction ID or TXID is an identification number for a Bitcoin transaction. It is an alphanumeric string that labels each transaction within the coin's blockchain. This differs from trade IDs, which are only associated with the trades made within the Paxful marketplace for receiving cryptocurrencies only. In comparison, TXIDs are recorded over the blockchain and work within the wallet for a Bitcoin trade.
Example.
9a2468889936b87b8d64211e1d2a36afebff6c73eaa8fa4a849cfe099076e723