What is a Auto Number?

Answer 1

Autonumber in Access is a special data type that, starting at 1, automatically adds a number for each line you add...

For example...

Say you were entering guests that were coming into a hotel. You would write

John Smith into the name field, and the autonumber field would automatically add the number 1 to it. The next record would automatically add 2 into the field. So it would look like

1 John Smith

2 Katy Jones

This makes it a more efficient way to write lists. The Autonumber field will not let you change the value, even if other records are removed, so ensuring that each record retains its own number.