You get the words, not the design
Each PDF page becomes one slide holding that page's text in a single box. Images, colours, fonts and positioning are not carried over.
This is a text rescue, not a design conversion, and knowing that up front saves disappointment. A PDF does not store slides, headings or bullet structure; it stores characters placed at coordinates. Recovering a designed deck from that is not something any converter can do faithfully. What this gives you is every word, already split page by page, in an editable .pptx you can build on.