When a site content type is associated with a list, a copy of the site content type is copied into the list, creating a new instance. The best approach to deploy content types is to use features (for more information about deploying site content types as a feature please click here).
Registering content type event handlers can also be achieved using a feature (check this article for more information) or by using Patrick Tisseghem’s Event Handler Explorer.
Content types basically define the metadata (they are composed by a reusable set of columns called site columns) and behaviors (event handlers, workflows, etc) of a certain category of content.
They are stored centrally and are reusable throughout a site or site collection depending on its scope.
For more information about content types please click here.
So what is the difference between a site content type and a list content type?
For those who don’t know, let’s start by a brief introduction about content types and explain the difference between a site content type and a list content type.
Content types are a new concept introduced in Share Point 2007 and is basically a reusable collection of settings that can be applied to a certain category of content.