A “release” is a person’s permission for someone to do something with their likeness that they cannot do without her permission. It’s just your permission given to someone else. In some areas permission has to be in writing, in others it can be verbal, or just implied by conduct. The term “release” in this case must simply demonstrate “consent”.
A release is (normally) a document that the model signs, but also could be a photographers release when the subject of the photos wishes to use them for any purpose. A “model release” is often written as a contract, but sometimes is not. A model release can be pages of legal verbiage, or as simple as “Jack, you can use my picture to advertise your beauty products.”
Consent does not have to be in writing, in many areas as you can give “a model release” to a photographer or a client by what you say, or what you do, if it appears that those things mean you agree to allow a usage of your images.
Suppose, for instance, you live in one of those states that do not require that “a release” (or consent) be in writing. You see an ad for models to do a swimsuit calendar, and you answer it. The client likes you, you are hired, the shoot takes place, and the calendar is published. You may find that you have trouble later making a legal objection to the publication, because you implied your consent to use of your picture in the calendar by answering the ad, even if no “model release” was signed.
A person has some rights to control or limit how her likeness is used. Those rights are granted by national or regional laws and vary depending on your jurisdiction. Some regions have very restrictive laws, others practically none.
Those are limited rights, not absolute. Once a picture is taken, and depending on how it was taken and what it is, there is still a broad range of ways that photographers and publishers can use pictures of you with or without your permission. It varies by region, but generally, use in newsworthy editorials, or in fine art, are permissible uses of your pictures without your written permission. Photographers generally can sell pictures of you too, without your permission, as long as they don’t sell them for impermissible uses. If you are a “public figure”, many of your privacy rights may not apply to most forms of publication.
The best way you can be sure that pictures of you will not be published or sold is to not have them taken in the first place. You can also enter into a contract with the photographer where he gives up his rights to the pictures, but that is very unusual, and pretty expensive.
You don’t own the photos taken. The photographer owns the photos and the rights to their use. That was decided with the copyright laws which are quite similar in most countries reading this. The photographer owns the copyright, and the right to publish the pictures. You can change that, if he is willing, by written contract, but it is a very unusual photographer will agree to that without payment.
The photographer owns them, and owns the right to control publication of them. To publish them yourself, you need a usage license or an agreement from the photographer. You may already have one, and him not know it, depending on the nature of the shoot.
Generally the photographer has the following exclusive rights:
(1) to reproduce the copyrighted work in copies;
(2) to prepare derivative works based upon the copyrighted work;
(3) to distribute copies of the copyrighted work to the public by sale or other transfer of ownership, or by rental, lease, or lending;
(4) to perform the copyrighted work publicly;
(5) to display the copyrighted work publicly
Exclusive means that the photographer is the only person who can do any of those things.
Agencies may use a voucher which serves many purposes and it may include a release. Discuss this with your particular agency.
If you aren’t on an agency-booked photo shoot you still may be asked to sign a Model Release. Sometimes no release is necessary or appropriate; other times they are mandatory.
For commercial shoots, where there is a product being advertised, a release is absolutely necessary. It is a foolish photographer/client who will shoot you without requiring one. Get used to it.
When “a release” is signed, what it says is negotiable. They may be blanket releases for any purpose or they may be releases for specific purposes. If this is discussed in advance then limitations may be added easily to any release if both parties agree.
THIS IS NOT LEGAL ADVICE. It is intended to help provide a general description of a release in order to dispel any myths that exist.