Open Database Connectivity (ODBC) is a widely accepted
application programming interface (
API) for
database access.
Developed by Microsoft, it is based on the Call-Level Interface (different than CLI) specifications from X/Open and ISO/IEC standards for database APIs and uses Structured Query Language (SQL) as its database access language.
You can access an ODBC database with a few lines of code in Visual C++, but there are programs for pretty much every platform that can access it, like FileMaker Pro for Mac.
According to http://www.microsoft.com/data/odbc/default.htm
ODBC is designed for maximum interoperability—that is, the ability of a single application to access different database management systems (DBMSs) with the same source code. Database applications call functions in the ODBC interface, which are implemented in database-specific modules called drivers. The use of drivers isolates applications from database-specific calls in the same way that printer drivers isolate word processing programs from printer-specific commands. Because drivers are loaded at runtime, a user only has to add a new driver to access a new DBMS; it is not necessary to recompile or relink the application.