Those lines are part of a script from a multi-signature transaction. The "OP" parts are operation codes, telling what to do with the data that follows.
The long strings starting with "3044..." are the actual signatures in hexadecimal format. To be valid, they must match the public keys and transaction details using crypto checks.
If they pass those tests on the Bitcoin network, yep, they're valid! 🧐✅🔒