Apple has joined the AI party.

The Cupertino giant confirmed Thursday that it has acquired Emotient Inc., a startup that says it can read human emotions using artificial intelligence.

The tech works by analyzing facial expressions and then using those expressions to interpret how people feel. Thus far, as The Wall Street Journal notes, the company has sold its product to advertisers who want reactions to ads.

On its website, Emotient describes itself as "the leader in emotion detection and sentiment analysis based on facial expressions," and that it believes it is "at the vanguard of a new wave of emotion analysis that will lead to a quantum leap in customer understanding and emotion-aware computing."

OK.

Buzzword-laden sentences aside, the technology seems interesting. It's worth noting that Emotient's prior business model seemed very business-to-business focused — this isn't a consumer technology company.

How Apple will use the technology is unclear. In a statement, Apple said it "buys smaller technology companies from time to time" and that the company "generally [does] not discuss our purpose or plans."

The Journal reports that Emotient was granted a patent in May for a method of collecting and labeling 100,000 facial images a day. This is presumably so Emotient's own cloud-driven tech can use that database to better and more quickly determine an emotion.

This isn't the first time Apple has acquired an AI startup. In October the company purchased VocalIQ, a British company focused on voice recognition and natural language processing.

Other companies are investing in AI tech, too, notably Facebook and Google.