odbc is driver, prolly a dll, that allows you to interact with particular databases. When you install MS Access on a windows box, you also instal a odbc driver. you can see this in the odbc administrator by looking at the driver tab. If you setup a data source in the administrator, it will preconfigure settings for an app to interact with a particular file.
i use odbc connections in ASP and PHP to interact with SQL, MS Access, Excel, & MySQL.
heres a good tutorial for using asp to interact with SQL. the CONN STRING at the top could easily be changed to interact with other types of databases
- click view ASP code to see conn string