Bitcoin Core Wallet.dat -

The public-facing identifiers used to receive Bitcoin.

If you: lose wallet.dat + have no backup + forget passphrase → Bitcoin Core Wallet.dat

You can usually find the wallet.dat file in the following default data directories: The public-facing identifiers used to receive Bitcoin

⚠️ There is no password recovery mechanism for Bitcoin Core wallets. If you forget your passphrase, your Bitcoins are lost forever unless you can brute-force the encryption—a computationally intensive process. Bitcoin Core Wallet.dat

To understand wallet.dat , you must first understand the difference between a "wallet" and a "wallet file."