ooGlossary.comAn object that, in general, carries instance data in its THIS scope instead of in its variables scope. It often has a validate() method to make sure the data is valid, but in general it can be looked upon as "a struct on steroids" and is typically used to pass data from, for example, a controller into a DAO to write data to the databse, or a controller may set a TO based on data from a DAO into an event object for display in a view:
You can sort of think of a TO as one of those South American tree frogs that carries a million little baby frogs around on it's back until they're big enough to go out on their own... a VO (or Value Object) is sorta the same thing, though it may be more like a marsupial in that it has a generic accessor (like setValue()) but still keeps everything in the variables scope whereas the TO has all it's data in THIS and a bean has all its data in it's variables scope and discreet get/set methods for each value.