What is meant by the first normal form in database theory?

First Normal Form (1NF) is a basic requirement for the structure of a table in a relational database. It means that:

• All fields in the table contain only atomic (indivisible) values.
• There are no repeating groups or arrays in a single field.

In simpler terms, each cell in the table should contain a single value, not a list or a structure.

For example, if a table has a "Phones" field, it should not store multiple numbers separated by commas in 1NF. Instead, a separate phones table should be created, linked to the main table.

This simplifies data processing and prevents anomalies during updates.