Access Data Types and Relationship

Data Type	Use for
Text	Use for text or combinations of text and numbers, such as addresses, or for numbers that do not require calculations, such as phone numbers, part numbers, or postal codes. Stores up to 255 characters. The Field Size property controls the maximum number of characters that can be entered.
Number	Use for data to be included in mathematical calculations, except calculations involving money (use Currency type).
Date/Time	Use for dates and times. Stores 8 bytes.
AutoNumber	Use for unique sequential (incrementing by 1) or random numbers that are automatically inserted when a record is added. (Note: the underlying data type for AutoNumber is Number, Long Integer.)
Memo	Use for lengthy text and numbers, such as notes or descriptions. Stores up to 65,536 characters.
Currency	Use for currency values and to prevent rounding off during calculations. Stores 8 bytes.
Yes/No	Use for data that can be only one of two possible values, such as Yes/No, True/False, On/Off. Null values are not allowed. (Stores 1 bit.)
OLE Object (Object Linking and Embedding)	Use for OLE objects (such as Microsoft Word documents, Microsoft Excel spreadsheets, pictures, sounds, or other binary data) that were created in other programs using the OLE protocol. {Stores up to 1 gigabyte (limited by disk space)}.
Hyperlink	Use for hyperlinks. A hyperlink can be a UNC path or a URL.
Attachment	Files, such as digital photo, Multiple files can be attached per record. This data type is not available in earlier versions of Access.

Relationships
One to many	In a one-to-many relationship, a record in Table A can have many matching records in Table B, but a record in Table B has only one matching record in Table A.
Primary Key	The Unique Identifier for each Record in a Table.
Foreign Key	Foreign key is used to link a primary key of another table. (A foreign key is a field in a relational table that matches the primary key column of another table. The foreign key can be used to cross-reference tables.)
Naming Conventions
Prefix for 3 major objects in access		(tbl, frm, qry)