Placing DB in a central system and use it from another systems

Yes, It is possible.

If your db server (or Machine where the SQL Server is installed) is in network then build a connection string in your application with the name of DB Server with require credentials. It will work.

When you create a connection to the DB you are likely going to use a connection string. This will be stored in you app.config file. It doesn't matter where this DB is, as long as the IP address it is sitting on is available to all computers from which you wish to access it.

There is a side note here worth mentioning: if you are storing username/password in the connection string you're going to want to look at encrypting your credentials[^].

Cheers.

Well all the solution given above looks good (although i have not tried them).But i would recommend you to use client server architecture. What basically you need to do is have an application which will run on the server where your SQL server is installed (this will be called server) and other application which will run on other machine (this will be called client). Now the client will always make request to server and (it will have no direct link with your database) server will process the request and send the output to client. For example let assume you need to save some data into database. The client application will get the data from user and send it to server and server will save the data into database.

I would recommend that you create a Windows Communication Service (WCF) on your server, which does all the updates to the database. Then you can create your windows/web application that uses this WCF service to fetch, insert and update your data.

Hope this helps