How is application familiarization implemented?

Question

C++ / C#

Tell me how they technically implement mini-learning at the first entrance to the program?
For example, when a translucent dark background is applied, a certain area on the form is highlighted, text is displayed, and a "Next" button is displayed.

Answer 1

This is usually not done on WinForms, because the translucency of window elements is not supported by default, you can hack it in different ways (example in the comments), but this is not very good.
For "acquaintance" use a different approach - tooltips. If the user clicks on a hint, the next one is shown. And when defocused, it disappears.