Layout drawings (レイアウト) are sketches of a scene. They will be more detailed than a storyboard, but still rougher than the final animation. Where a final animation drawing will be dedicated to a particular cel layer, a layout drawings will generally contain elements of the entire cut (often including multiple characters, objects, and background elements). The drawings literally "lay out" the scene in deference to the storyboard and are a reference for both the key animator and the background artist. Original layout drawings are often produced by the key animator of a scene. In some larger productions studios, specialized layout artists may be hired.
Collector's Note: Layout drawings will often come as a set with backgrounds or final animation drawings. However, you may also see them being sold separately.
Original Hand-drawn Layout from Saiyuki Reload: Burial OVA - Of Son Goku Episode 2, this show was computer animated although all of the sketch work and backgrounds were done on paper.
Layout Copy from Episode 54 of Card Captor Sakura of a young Kinomoto Touya came with original cel, Douga, and Copy BG. I posit the BG and the original layout were sold separately.
This is a photocopy of an original layout drawing. It is common practice for the layout to be copied and distributed to the necessary people in a studio (key animator, background artist(s), etc).
Collector's Note: Like original layout drawings, layout copies are commonly paired with backgrounds or other drawings when sold on the collector's market. Unsurprisingly, layout copies are more common, less desirable, and less expensive than their hand drawn counterparts.