In ships, frames are ribs that are transverse bolted or welded to the keel.
Frames support the hull and give the ship its shape and strength.
[1] In steel shipbuilding, the entire frame can be formed in one piece by rivetting or welding sections; in this case the floor remains a separate piece, joining the frame on each side to the keel.
Frame numbers typically begin at 1 with the forward-most frame for US-built ships, and typically begin at 0 with the transom for ships built elsewhere, with numbers increasing sequentially towards the stern or bow, respectively.
[2] The frames support lengthwise members which run parallel to the keel, from the bow to the stern; these may variously be called stringers, strakes, or clamps.