Sorry I'm not getting very far. I think I need to go back a few steps.
I don't have a mental picture of this 'connection' bit. I am a complete beginner with SQL Server and VB.NET. All my experience is with MS Access, and this is how I see things (don't laugh):
An Access db exists as a mdb file, within which are the tables and the queries that link them and make them do clever stuff, as well as all the fancy forms and reports that the user interacts with. I guess the mdb file is analogous to the server, and each instance of Access used to gain access to it is a client.
In moving from Access to SQL Server, I guess what I'm doing is I'm setting up a server with a mdf file on it. I've created a basic mdf (using SQL Server Management Studio) with a single table, just to practise, and I'd like to create a simple VB application to display data from that table, allow me to edit, enter new data, query the data etc. At the moment the stumbling block is getting my VB.NET project to talk to my mdf file. I must confess to be a bit in the dark here.
I think I need to create a connection string, in which I identify the server (which is presumably somewhere on my C drive) and the database (likewise), and provide user and password details. Trouble is, although I can find examples of connection strings online, I've no idea which to use or where to put it.
Does the SQL server connection string do the same job as the MS Access shortcut I'm used to, which points to 3 things: the MSAccess.exe file, the mdb file itself, and the workgroup security file?
Could some kind person walk me through the first few steps? Assume no prior knowledge. Thanks.