The Keurig k cups are the body and soul behind Keurig's innovation. Every one is separately sealed for freshness, and within is a paper filter filled with Tea leaves.
The Keurig Coffee Maker puts a hole in the top of the cup and a hole in the bottom. The water passes through the Tea leaf premises and through the filter. The Tea then comes out the hole at the bottom and into your mug below.
Learn More About Single serve Cups here