To allow Windows users to reuse their existing skills to create new applications, Microsoft extended this OLE linkage to Visual Basic. Natively Visual Basic has things like Menu Objects and Button Objects. When connected to Excel, Visual Basic also has Workbook objects and Cell Objects. The Excel Objects look the same and work the same as native VB elements. A VB program can tell Excel to load an XLS file, plug some numbers into selected cells, recalculate the spreadsheet, and pick up the results.
Word handles compound documents containing formatted text and embedded pictures.
So does a Web Browser. Excel, Access, and Visual Basic can provide basic data entry panels in which the user types a few numbers to trigger a query or a calculation. So, with HTML forms, does a Web Browser. Just as Microsoft Office needed an automation language, and chose Visual Basic, so Netscape realized that the Web needed some light weight automation language, and chose JavaScript. Netscape also looked at the way that Microsoft created Objects for its Office applications, and decided to do the same thing with its Browser.