dishankb

I am a researcher and most of the times, I am studying different of topics say algorithm, linear algebra, deep learning. It becomes difficult to organize the material of each topic separately. The material can be anything like hand notes, websites link, images. And different methods are suitable for different type of material like for websites, bookmarks in a topic wise folder work well, for hand notes images, local folder topic wise in pc works well. Can anyone help me with their material organizing methods, which can help me to organize different types of material at one place for each topic?