Which one of the following is true of joins
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Joins are between two tables
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Joins cannot be updated
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Joins are used in multi value groups
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Joins are created in the client
SQL joins fundamentally operate between two tables (or table-like objects) by matching related columns. While some databases support joining more than two tables in a single query, the basic join operation always involves exactly two tables at its core. Joins are server-side operations and can be part of updatable views.
In basic relational database and query-tool terminology (e.g., Access, FileMaker, simple SQL joins), a join fundamentally connects two tables based on a related column, forming the basis of relational queries; more complex queries can chain multiple joins but each individual join operation is still a pairing between two tables. Joins generally can be used in updatable queries (so "cannot be updated" is false), aren't inherently for "multi value groups" (a distractor with no real meaning here), and are defined at the database/query level, not merely "in the client" (a UI/application layer). So "Joins are between two tables" is the best true statement among the options.