A Model Release is a formal agreement between the model and the photographer.
By signing the Model Release, you acknowledge that images with you in them will be made available for commercial purposes around the world.
The microstock agencies that will sell your images have a long set of ‘user rights and restrictions’ that protect you and the photographer (me) from abusive or defamatory usage of the images. Restrictions are so tight that misuse almost never happens, and any that attempt it have prompt legal action taken against them to stop it. This is important to us all so that models, photographers, and the industry as a whole can be protected and continue to operate.
For models who are minors (under 18yo) a parent or guardian must complete and sign the Model Release on their behalf.