In addition to size, hooks are often described in other ways, let’s call these “X Factors”. A number followed by an “X” can be used to represent shank length, the diameter of the wire used to make the hook or the hook gap also called the gape.
With shank length, a hook can be described as short or long. A 1X short is just slightly shorter than a standard length hook, while a 2X short is even shorter than the 1X. A 3X is shorter still.
Going the other way, when a hook is listed as a 2X long, its shank is longer than that of a standard hook. Here, as the X number increases, so does the shank length.
Wire diameter is often described as “fine” or “strong”, which some brands call “heavy”. So a hook made with smaller diameter wire than the standard one might be labeled 2X Fine, while a hook made with heavier wire could be designated a 2X Heavy.
For gap or gape, the number and the X generally refer to a wider gap than normal, as in 2X wide gap.
Oftentimes, multiple “X Factors” are used to describe a hook.