It is the bridge over the data chasm. It is the diplomat in the war of the databases. It is the only piece of software that has ever looked at Oracle’s ego and Microsoft’s stubbornness and said, “Fine, I’ll make them talk to each other.”
The answer is unglamorous, frustratingly finicky, and absolutely indispensable: driver odbc oracle
The driver becomes a living entity, a malevolent spirit. You try the "Oracle ODBC Driver" (deprecated). You try the "ODBC Driver for Oracle" from Microsoft (old, buggy). You finally find the "Oracle Instant Client" (the holy grail), but you forget to set the TNS_ADMIN environment variable. The machine rejects you. It is the bridge over the data chasm
You spend the next hour in a state of existential dread, trying different versions of the driver. Do you need the 32-bit driver or the 64-bit driver? (Spoiler: Your OS is 64-bit, but Excel is 32-bit, so you need the 32-bit driver—good luck finding that in the documentation.) You try the "Oracle ODBC Driver" (deprecated)