TED's Creative Commons BY-NC-ND license allows you to display TEDTalks under the following conditions:
Attribution (BY): You must explicitly reference TED as the original source of the materials, and TED's logos within the videos and visuals as well as those of the TEDTalks sponsors remain untouched and unedited.
NonCommercial (NC): You can't use TEDTalks (or any parts of them) for commercial purposes. If you are a company wishing to create a TED branded content offering, you will require a Distribution Partner License Agreement with TED. Please contact Deron Triff, Director of Content Distribution, to explore the opportunity.
NonDerivative (ND): You cannot alter the videos in any way. This means you cannot edit, remix, cut, shorten, add overlays to them, or, well, alter them in any way.
These conditions can be modified only by explicit permission of the copyright holder (TED Conferences LLC). The complete text of the license can be seen on the Creative Commons (CC) license.