For my experience, I would say (ADO) Active Database Object in (VBA)Visual Basic Applications.

I learn first computer with application of Lotus-123 way back in the '80s. Then migrated to Excel, the Excel Macros to Access
database. To Access VBA, either (DAO) Database Active Objects or ADO, in OOP. Learning ADO, made me understand the concept of (OOP) Object Oriented Programming.

I still learning HTML, CSS, JavaScript, XML, XSLT, PHP & MySQL.
Maybe it is not for others, but as I learn more I understand that
almost all languages are leaning towards this direction.

John