Belgian beer is not one thing and the pages on this site do not all do the same job, so the useful question is which one you came for. If you want the styles and what separates a dubbel from a tripel from a quadrupel, start at the Belgian beer guide. If you want to know what a certified label guarantees before you pay for it, that is a different page and a different set of facts.
The Four Questions This Cluster Answers
Whether a brewery can call itself Trappist is a legal and monastic question, settled by who owns the brewery and where the money goes, and the requirements are set out in what the Trappist label guarantees. Abbey beer is a separate claim and the two get confused constantly, which is what abbey beer versus Trappist exists to untangle.
Saison is the farmhouse style most often mislabelled today, and the brewing and drinking detail is in the saison guide. The Belgian yeast question travels further than Belgium, and the corridor that matters for a British Columbia reader is the one into Quebec, where the yeast strains and the brewing families moved across a border rather than an ocean, which the Quebec and Belgium page covers with the local breweries named.
What Belgium Actually Exported
The short version of the argument this page used to make at length: the durable Belgian contribution to world beer is yeast character and serving practice rather than any single recipe. The mixed-culture fermentation behind sour beer, the habit of pairing a specific glass to a specific style, and the cellar tradition that produced farmhouse ales are the three things other countries took and kept. Everything else in the Belgian category is a style list, and the style list is on the guide linked above rather than being repeated here.
