Turning my comment into an answer and adding an example:
A frame is a collection of slides that share a common code (that could contain commands like \alt or \only etc that will give the difference between the slides inside this frame).
Compile this example to understand more. It contains two frames with a title each... but the first frame is composed by ...
From a Commentary on the German TeXWelt I got the following hint:
The beamer theme Focus (see GitHub - elauksap/focus-beamertheme: Focus: a minimalist presentation theme for LaTeX Beamer.) is a good starting point.