VBA stands for Visual Basic for Applications, and is a programming language subset of Microsoft Visual Basic. With VBA, users can control several options in programs such as PowerPoint that support VBA.
Most Microsoft Office applications such as Word, Excel, and PowerPoint work with VBA. There is an extensive amount of information available online, including at the Microsoft site about VBA. There are also many VBA users who are always ready to help others -- you can find many questions about VBA in Microsoft Office applications answered in the Microsoft Answers forums. Although VBA is supposed to be giving way to new technologies such as VSTO in Office 2007 and later versions, many programmers still love to work with VBA.
The best part is that you really don't need to learn a lot of VBA to make things happen. Sometimes, you can just paste a snippet of VBA code to make miracles happen!
For examples and easy ways to work with VBA, you can find some sample VBA code here that shows how you can add a spirograph type graphic in PowerPoint.
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