Review of 'What is a mole?' link

I was able to read the website's explanation of the mole with clarity and some understanding. I liked the way it was written and felt that the information was concise. However, the information is so dense and unfamiliar to my mind that I needed to go over it several times, which I didn't mind too much but it was slightly cumbersome only because it took so much concentration to really feel like I was even slightly grasping the content. I chalk this up to familiarity and the more I get familiar with the concepts, the easier it is to digest them.