A manga appears first in a magazine, then in standard volumes, and, if it lasts, in reissues: larger premium editions, smaller cheap ones, omnibuses and digital colour versions. Each repackages the same chapters, which is why volume counts disagree. Read from the structure, as a 4.
4Four — foundation. That is the reduction of this question, and the shelf it is read from.
In Japan most manga begin as chapters in a magazine, weekly or monthly. The magazine is cheap, printed on recycled paper, and read once. It is the first version of the work, but rarely the one people keep.
Chapters are then collected into tankobon, the standard paperback volumes, typically around 200 pages and nine or ten chapters for a weekly series. This is the edition a volume number normally refers to: when people say a series is "34 volumes", they mean tankobon.
The tankobon is also where authors revise. Pages rushed for a weekly deadline are redrawn, mistakes fixed, and bonus material added: author comments, character sheets, short omake comics. For many readers it is the definitive version.
When a series becomes a classic, it may get a kanzenban, a "perfect edition". Pages are larger, volumes thicker, colour pages from the magazine are restored, and covers are newly drawn. Because each book holds more, the volume count falls. Dragon Ball, 42 volumes in its standard edition, runs to 34 in kanzenban.
The bunkoban goes the other way: a pocket-sized reprint that packs more pages into each smaller volume, keeping older works in print cheaply. There are also wide-ban editions, larger and closer to the size of an American trade paperback, and convenience-store reprints of popular arcs on cheaper paper.
English publishers usually follow the tankobon numbering, so volume 5 in English is volume 5 in Japanese. The main exceptions are omnibuses, which bind two or three volumes into one book, and deluxe hardcovers. Check an omnibus's spine carefully: "volume 3" may contain Japanese volumes 7 to 9.
Digital editions generally follow tankobon numbering too. Some popular series also have full-colour digital editions in which every page has been coloured after the fact, a different reading experience from the black-and-white original.
For most readers the standard volumes are the right choice: they are complete, revised and easy to find. Kanzenban are worth it for a favourite classic, especially for restored colour. Bunkoban are a good value for older series if small print does not bother you.
Every letter here carries a digit; together they make 193, which folds down to 4. The weight sits in “Explained”, which carries 45 on its own and reduces to 9.
Four is builder & organizer — structure, labour, and the building of lasting systems. The reference files it as a structure. Read that way, what the explainer is really recording is the 4's insistence that what lasts must be built patiently.
The vowels alone reduce to 9, the consonants to 4. Reckoning underneath, foundation on the surface. The gap between them is where the subject is most interesting.
The 4 confuses the frame for the work. Structures outlive their usefulness, and several entries here describe conventions kept long past their reason. What the 4 still asks is that you look for the constraint the subject was working inside. The other explainers that reduce to 4 are collected on The Structure.