Teaser, announcement, or actual launch?

Could someone explain the practical distinction the news team uses between a teaser, a product announcement, and a launch?

I see those words used interchangeably elsewhere even when the product is not actually available.

A teaser signals that something is coming but may provide little usable detail. An announcement identifies the product and gives substantive information. A launch means the product has entered the market or the company has provided a concrete release event or availability path.

That is much clearer. So “announced” and “available” should not be collapsed into the same date.