In relational terminology, an attribute is best defined as which of the following within a table (relation)?

Introduction / Context:
Relational vocabulary maps everyday database objects to formal terms. Correctly matching “attribute” clarifies subsequent topics like functional dependencies and normalization.

Given Data / Assumptions:

• “Attribute” is a formal term from relational theory.
• Tables (relations) are composed of rows (tuples) and columns (attributes).
• Keys and indexes are separate constructs.

Concept / Approach:
An attribute is the column definition—name and domain (data type)—for values stored per row. Attributes collectively define the schema of the relation.

Step-by-Step Solution:

Verification / Alternative check:
Any relational database textbook or SQL standard-based glossary reflects this mapping.

Why Other Options Are Wrong:
Two-dimensional table / row / key / index: Those are different concepts; an attribute is not a whole table, a row, a key, or an index.

Common Pitfalls:
Confusing attribute with field in certain contexts; “field” is an implementation term, while “attribute” is the relational theoretical term.

Final Answer:
column of a table.