PUPILCLIP is just like YouTube. In pupilclip user search the videos by categories leave the comment like and dislike video. But for leaving comment user need to sign in. if user do not have the account in pupilclip then user can register yourself by filling the registration form and chose their user name and password. After get sign in. user can upload the video make video public privet unlisted. If user makes video public that means video can be watched by everyone.