Column or columns uniquely identifying a row.

Returns all left-table records and matching right records.

Web interface element used to collect user input.

Older security protocol historically used for encrypted connections.

Field referencing a key in another table.

Returns all right-table records and matching left records.

Checking whether input meets defined requirements.

Cryptographic protocol securing network communications.

Field or fields that could uniquely identify records.

Returns records from both sides, matching where possible.