Retyping a passage from a PDF is a waste of time when the words are already in the file. Extract text pulls them out as plain text you can copy, translate or paste elsewhere.
Most PDFs carry a text layer: the real characters that make the document selectable and searchable. Extraction reads that layer directly, in your browser.
A scan is only a picture of a page, with no text layer, so there is nothing to extract. Run it through Make PDF searchable first: it reads the text in the picture and adds it to the file. Then extract the text.
You get plain text: columns, tables and font styles are not kept, and page breaks become blank lines. To keep the layout, convert the PDF to Word instead.
Do it now: Extract Text