Seriously, what's the difference? Well, I'm gonna look them up, because I don't know them, and I doubt you do either.
Deck - A roofless, floored structure, typically with a railing, that adjoins a house
Porch - A covered platform, usually having a separate roof, at an entrance to a building.
Patio - An outdoor space for dining or recreation that adjoins a residence and is often paved.
Portico - A porch or walkway with a roof supported by columns, often leading to the entrance of a building.
Veranda - A porch or balcony, usually roofed and often partly enclosed, extending along the outside of a building. Also called gallery.
Balcony - A platform that projects from the wall of a building and is surrounded by a railing, balustrade, or parapet.
Stoop - Originally, a covered porch with seats, at a house door; the Dutch stoep as introduced by the Dutch into New York. Afterward, an out-of-door flight of stairs of from seven to fourteen steps, with platform and parapets, leading to an entrance door some distance above the street; the French perron. Hence, any porch, platform, entrance stairway, or small veranda, at a house door.