A classic form of tiling puzzle with flat physically interlocking pieces
A jigsaw puzzle is type of tiling puzzle. It's primary features are shapes cut to form an interlocking pattern which form to build a familiar image.
The pieces of a jigsaw puzzle are flat. Even in 3d puzzles, such as those that form a globe, the pieces are flat on the plane of the puzzle. The pieces physically lock together, such that the entirety of the pieces have a single solution with all the pieces correctly connected. The flat pieces, shaped cuts, and locking aspect, are the key defining characteristics of a jigsaw puzzle. Tiling puzzles without these properties are not called jigsaw puzzles.
Jigsaw puzzle pieces are often used to divide clues into a game. Players may need to find several pieces, which when connected reveal a clue.
A linear jigsaw puzzle is a set of tiles that fit together to form a single line. The line need not be straight, but each piece only connects to two others. As this creates a clear ordering to the pieces, the order itself can be used as a clue.
Assume everything in this reference is a working draft, there's prone to be some mistakes and inconsistencies. I figure it's best to publish and get feedback rather than write for years in secret. The terms will change, the structure will shift, and the bugs will be chased out. It'll take a while.