After you enter field names, you'll need to set the data type for each field. Data types control what you can enter into a field. For example, if you set a field to the Date/Time data type, you can only enter dates and times in that field, and that helps ensure you enter data accurately.
Note You may not need to set a data type for some fields. Access automatically sets new fields to the Text data type, so for any text fields, you can leave the data type alone.
Select the field that needs a data type. Just click the field header.
If it isn't already selected, click the Datasheet
In the Data Type & Formatting
group, open the Data Type
list and select an option.
If you're unsure about which data type to choose, look at your field names. For example, if you have a field called Acquired_Date, chances are you can set it to the Date/Time data type. If you're unsure about which type to select, stay with the Text data type because it's the most flexible. And don't worry about making a mistake. At this stage, while your fields don't contain any data, you can easily change your data types.