Would I ever want to configure a field with the AutoNumber format?
Your data might require a unique sequential number for each record, such as an invoice number. Most often, however, Access uses the AutoNumber format for the key field that is added when you don't specify a key field.
Can I enter data in the Datasheet view?
Certainly. As explained in this and the next hour , the Datasheet view is a handy view for entering simple data and for viewing multiple records of data from a table. The Datasheet view offers a worksheet-like view of your data in a row and column format. The Datasheet view gives you quick access to a table's data.
Remember that a Datasheet view shows only a single table's data. It does not show the entire database because a database often contains multiple tables of data.
Can a key field contain duplicates?
No. If you have to locate records by field and that field is not unique, you cannot make the field a key. You must decide on another key or let Access add the key field.