The site offers access to video tutorials for Biology, Chemistry, Organic Chemistry, Physics and Calculus. Each subject is organized into a separate page with the topics for each subject organized by into sections, each section provides a series of videos from educators who have been invited to share their material.
The Socratic site is clean and easy to navigate. All of the videos that I have viewed have been extremely helpful and well made. The lead educator is Tyler DeWitt. Who does an outstanding job of presenting material in a clear and a concise manner. He breaks the material down in such a way that it is logical and easy to understand. Some of you may have seen his TED Talk - Hey Science Teachers --- Make It Fun.
Currently for Chemistry, Socratic provides the opportunity for students to post questions for the Socratic team of educators to provide explanations or solutions.
I have incorporated videos from the site as support and reinforcement for my owned flipped lessons.
Here are some links to examples of the Socratic site.