: Most educational platforms provide a direct link. Clicking it often opens the PDF in your browser; from there, you can click the Download (down-ward arrow) or Save icon in the top toolbar.
If you are required to write a report about the lecture material you downloaded, standard academic guidelines usually include: Download SECOND LECTURE pdf
: If the PDF is embedded directly on a webpage, right-click the document and select Save as... to choose a location on your device. : Most educational platforms provide a direct link