1NF

First normal form (1NF). This is the "basic" level of normalization and generally corresponds to the definition of any database, namely:

* It contains two-dimensional tables with rows and columns.
* Each column corresponds to a sub-object or an attribute of the object represented by the entire table.
* Each row represents a unique instance of that sub-object or attribute and must be different in some way from any other row (that is, no duplicate rows are possible).
* All entries in any column must be of the same kind. For example, in the column labeled "Customer," only customer names or numbers are permitted.