Relational Database Concepts

Field

A single piece of data/attribute in a database, represented as a column in a table (e.g. Surname).

Record

A complete set of related field values, represented as a single row in a table (e.g. one specific person's full details).

Table

A structured collection of related records, made up of rows (records) and columns (fields).

Primary key

A field (or combination of fields) that uniquely identifies each record in a table — no two records may share the same primary key value, and it cannot be left empty.

Database schema/structure vs data — the schema is the design/blueprint of the database (table names, field names, field types, keys), while the data is the actual content stored within that structure. You can have an empty database with a defined schema but no data yet.