difference between topic and category

[Marcus]

I'm a little confused about the difference between topics and categories... I'm assuming topics are sub-categories, but then when i compare the data it doesn't add up. The fact that v3 has topics and only v2 has categories confuses me more, not sure if it's still not implemented or something else.

Example from the api console:

/2/categories blank search partly returns this for me

• {
  • "name": "Cars & Motorcycles",
  • "sort_name": "Cars & Motorcycles",
  • "id": 3,
  • "shortname": "Auto"
  },

/find/topic_categories with a blank search has this:

• "0": {
  • "id": 242,
  • "shortname": "outdoors-adventure",
  • "name": "Outdoors & Adventure",
  • "sort_name": "Outdoors & Adventure",
  • "photo": {
    • "id": 450131943,
    • "highres_link": "http://photos1.meetupstatic.com/photos/event/2/e/a/7/highres_450131943.jpeg",
    • "photo_link": "http://photos1.meetupstatic.com/photos/event/2/e/a/7/600_450131943.jpeg",
    • "thumb_link": "http://photos1.meetupstatic.com/photos/event/2/e/a/7/thumb_450131943.jpeg",
    • "type": "event",
    • "base_url": "http://photos1.meetupstatic.com"
    },
  • "category_ids": [
    • 3,
    • 23
    ]
  },

So, at this point I'm thinking since 3 is in the category_ids array in the topic_categories result, that means that topic can reside in 'Cars & Motorcycles' and also category_id 23 which corresponds to name 'Outdoors & Adventure'.

However, looking at the topics page, that is not the case - https://www.meetup.com/topics/ - "Outdoors & Adventure" is in fact a top level topic or category, or maybe another terminology :)

I hope someone can shed light on that situation.