Primary Key.
In a database, a field that uniquely identifies a particular record in a table is called
primary key
Because it uniquely identifies each record in that table, No two records can have the exact same entry in the field designated as the primary key.
A field that uniquely identifies a particular record in a table is called a primary key. The field or fields on which records are sorted is called the sort key.
record
A unique key is used to enforce uniqueness of each row in a table. A unique key comprises a single column or a set of columns. No two distinct rows in a table can have the same value (or combination of values) in those columns. A primary key is simply a NOT NULL unique constraint. Table can have only one primary key, but many unique keys.
A field.
When used as a database, an identifier in Excel identifies a record, so it acts like a primary key field. You can then find records easier.
The field or combination of fields, the latter is called a composite key, which uniquely identifies a record. Often people use an integer automatically assigned at record creation, however, if possible it is best, to try for a field which is a unique attribute of the entity a table is describing.
A field in a database holds one item of data relevant to a record. Each field represents a specific piece of information, such as a name or a date, within a record.
This field is usually called the primary key field