In blockchain security, the pseudonymous nature of certain blockchains keeps a network user's identity hidden from other network users while still linking all of the transactions made by that person to a pseudonymous identity that CAN be tracked by almost anyone
Example
“A Bitcoin wallet address like '1A1zP1eP5QGefi2D...' acts as a pseudonym — anyone can view its transaction history on the blockchain, but the real-world identity behind it is not directly revealed.”