Microsoft Jet uses a variety of components, implemented as dynamic-link libraries (DLLs). These DLLs constitute the Jet database engine as a whole. The Microsoft Jet DLLs can be grouped into the following component groups:
| DLL group | Description |
| Microsoft Jet DLLs | Responsible for storing data in the database file and for providing query and security services. |
| Data Access Objects (DAO) DLLs | Responsible for providing the programming interface to the Jet database engine and ODBCDirect. |
| External ISAM DLLs | Responsible for providing access to external (non-native) data (for example, Microsoft Excel, Microsoft Exchange, HTML, Microsoft FoxPro, Borland dBASE, Corel Paradox, and Lotus 1-2-3). |
| Replication DLLs | Responsible for creating and synchronizing full or partial database replicas at multiple locations. |
| Visual Basic for Applications (VBA) DLLs | VBA is not a component of Microsoft Jet, but it provides the expression service to evaluate functions in SQL statements. |
| Open Database Connectivity (ODBC) DLL | In addition to the components discussed above, Microsoft Jet uses the ODBC Driver Manager DLL to provide access to ODBC data sources. |