Translate Snooker Club Handicap Jargon for a Brand New Member

The noticeboard lists names, numbers and division letters, and nobody explains any of it to a new member. This translates the handicap and ranking system into plain English: what the handicap actually changes in a frame, how it updates, and what your division says about the standard around you.

Translate a snooker club's handicap and ranking system into plain English for someone who has just joined and has no idea what the numbers next to their name mean. Explain what a handicap actually adjusts in a frame, how it's calculated or updated after results, and what the different internal league divisions typically signify about standard of play. Use [a new member's first handicap sheet or club noticeboard listing] as the kind of thing being explained.