The same words carry different intents. "SEO agency" from someone comparing providers calls for a list with prices and reviews; "what is an SEO agency" calls for an explanation. Google reads the intent from the behaviour of millions of searchers and shows the format that satisfied them, which is why the SERP for a query tells you its intent.
Matching intent is the first decision when writing a page: one intent, one page. A product page stuffed with a definition serves neither reader. On a directory such as SeoGeoMap, the listing pages serve the comparing intent and the guides serve the learning one.