It's all kind of up to the author's preference, there's like infinite ways to do it lol
In a big-picture sense, a lot of long story-based comics are either divided into chapters or "seasons". A chapter is fairly self explanatory. "Season" is used loosely in a way similar to like a television series where it might contain the amount of content that would typically occupy several chapters, and might be thought about similar to like a graphic novel compilation or like a manga volume. Sometimes a season will even have several chapters contained within and other times it'll just be one long stream of story until the season finale. In either case it's common for the artist to take a break after either the conclusion of a chapter or season before starting or posting the next one. The only main difference that I can really pinpoint is that seasons are often (but not always) longer than chapters.
On the smaller scale, update/episode are typically used interchangeably to refer to a single post that the author makes, but the format and length again vary a lot author to author. The two main distinguishing factors here are whether the author uploads in pages or the vertical scroll format.
Pages are, again, fairly self explanatory. They usually have 1-8 panels and you might post one or more on a single episode/update. If posting in vertical scroll, it's not much different, just the episode would be counted in total number of panels instead. In either case, it's up to you how many pages, panels, or updates your comic will need to complete a chapter or season. No casual reader really cares about the specific totals, I think. At worst you might hear people say "your updates are too short", but even then there's not a specific amount they're looking for- they just want as much as possible lol
