In relational database theory, a relation is best described as what kind of table?

Introduction / Context:
The term relation has a precise meaning in relational database theory. Understanding its structure is foundational for normalization, keys, and query formulation.

Given Data / Assumptions:

• Each relation has attributes (columns) and tuples (rows).
• Cells contain atomic values under first normal form assumptions.
• Ordering of rows and columns is not semantically important.

Concept / Approach:
A relation is modeled as a two-dimensional table: one dimension for attributes (columns) and one for tuples (rows). This abstraction allows the use of operations like selection, projection, and join.

Step-by-Step Solution:

Verification / Alternative check:
Relational algebra operations work on sets of tuples with defined attributes, consistent with a two-dimensional structure.

Why Other Options Are Wrong:

• Column or one-dimensional table: ignores the row dimension.
• Three-dimensional table: not applicable to basic relational structures; multidimensional models belong to OLAP cubes, not base relations.

Common Pitfalls:
Confusing relations with multidimensional cubes or hierarchical structures. The relational model is simpler and strictly two-dimensional.

Final Answer:
two-dimensional table.