What Exactly Are Keywords?

I looked at a website and companion Facebook (business) page that consisted of such generic words that people would not use those words to search for what the site had to offer.

The website owner needed to clarify her brand and then use keywords based on that brand in a new Facebook page whose title could be keyword searchable inside and outside Facebook.

Then the more I thought about "keywords" the more I realized that the meaning of this might not be clear.

I googled "keywords" and came up...