Pastry is a form of baked dough, usually used to hold filling, whether sweet (like an apple pie or cherry pie) or savory (like a pork pie or chicken pot pie).
As with most examples of the culinary arts, pastry is found in many forms, from a simple layer of dough used as described above, to elaborate versions using layering techniques to form a more sophisticated physical presentation, like danish pastries or baklava.
The word is also used to refer to the entire dish at times, as in "have a delightful home-made pastry".