Image Tags and Key Words

I recently upgraded to Mavericks (and a new MacBook Pro) and just bought a software program called HoudahSpot, which is sort of an advanced version of Finder/Spotlight. Among the items you can list as search criteria are the following:

Keywords

Keywords and Tags

Mavericks Tags

Open Meta Tags

Spotlight Comment

Can anyone tell me what these are and what software programs are needed to apply them?

I have a general knowledge of keywords and tags. I know you can apply keywords with Aperture, but they're lost when you export an image to a website, I believe. I've also been told you can apply keywords (and tags?) with Photoshop and Lightroom.

I've just discovered Mavericks' colored tags (red circle, etc.). Is that what they mean by "Mavericks tags"?

To put it in better perspective, imagine an image named ak-tree.jpg. It's a photo of Alaska's state tree, and I might like to add tags indicating the species (Sitka spruce), class (conifers) and perhaps the location (Alaska) and a green dot to indicate a plant. What software program(s) do I need to accomplish this?

Thanks.