Every version of this article the database has kept, newest first. Each row is one save: the whole page as it stood at that moment, not a patch against the one before it. Pick any two and compare them line by line.
The size column measures the article’s markdown source, frontmatter included, which is the same measurement the database stores and the same one a diff is computed over. A revision that changes status from emerging to contested moves the byte count by a handful of characters and is one of the largest editorial changes this wiki can make; size is not importance.
cur compares a revision against the version now live. prev compares it against the one it was written on top of. A revision with no prev is the first version of the page, and there is nothing behind it to compare with.
Two saves made against the same starting revision cannot both succeed — the second is refused rather than allowed to overwrite the first — so this list is a straight line, not a graph with branches to reconcile.