Allows more data as Access has a limit
But if you're getting to that you should prob move to SQL Server

One backend is very useful. More than one, and relinking the backend becomes more complex if you have many tables.

I have one database for my forms, then have multible backends that I switch between with the main form with a combo box. One for my family, one each for friends of mine.  If I make a field change, I just have to remember to put it in all three backends. But that way if I make a form design or a new report, I just have to do that once.

Hi Sandra,
In your case, the relinking can still be automated because the frontend is only linked to one backend at a time.
If you have your backend compromised of let's, say 2 backend files, then to switch between your family and your friend becomes tedious as you have to name each table in your relinking. You no longer can loop through the tabledef and re-link.

Is it possible for a frontend application to connect to multiple backend systems based on the type of information being requested or submitted by the user? For instance, consider a scenario where employee data and vehicle information are stored in separate backend databases. The frontend interface could seamlessly integrate and display data from both sources. This integration would allow users to access comprehensive reports that draw on information from the EmployeeT and VehicleT databases, enabling more holistic insights and facilitating better decision-making. The frontend can dynamically query the relevant backend systems based on user input by utilizing appropriate API calls or microservices, ensuring that the most accurate and up-to-date information is presented.

The backend is responsible for storing and managing information, while the frontend handles processing this data through various means such as queries, forms, and reports. The interaction between the two layers enables users to retrieve, manipulate, and present data as needed effectively. However, I am uncertain about the feasibility of using junction tables to create connections between information stored in tables that reside in different backend systems. Junction tables are typically utilized in many-to-many relationships within a single database. So, I'd like to know how they might function across disparate backends and whether this could facilitate integrated data retrieval or management.

The data could be anywhere
Flat files, Access DBs, SQL Server, SharePoint, Azure.
You can connect as many as you want.
As long as you then have the Queries on the FE to do the joining.
Can't say how fast it would be like that though.
If it's getting into that territory it might be worth building a .NET WebApp or equivalent.

The answer to most of the questions you posted in the last 2 post is "Yes", however, your understanding of how Access connects to a backend(s) is off.

Once you have linked the backend files in the frontend, The frontend treats all the tables from all the Backends as available to it. I have Frontend linked to tables in SQL Server, Local tables and Second backend Access file. to the frontend, they are just tables.