Microsoft Access accepts 10 data types: attachments, AutoNumbers, currency, dates and times, hyperlinks, memos, numbers, OLE objects, text, and yes/no Boolean values. The data type is defined by the qualities that apply to all values in the field. For example, text fields only contain letters, numbers and some punctuation characters.
AutoNumbers are used to keep count of records in a table, and the value is insignificant. A hyperlink can store up to 2048 characters of a URL or a UNC path. Memos are blocks of text of more than the 255 characters allowed in a text data type field.
OLE objects are specific types of attachments, such as Microsoft Excel Spreadsheets, attached one by one. Attachments data fields accept more file types. The Boolean value field can use True/False, Yes/No or On/Off.
The data type of a field dictates many other field functions, such as which formats can be used, how the field can be used in expressions, the maximum field value, and whether the field can be indexed.
To create a data field, enter data into an empty column and adjust the data type and other field properties with the Datasheet tab. Fields created with templates in Datasheet view have predefined properties.