Puer is a sub-category of Dark Tea that comes from Yunnan province in China. Puer teas can be the strongest teas in the world. They can also be medium-bodied, bright, and slightly sweet depending on how you prepare them. Puer teas typically are aged and are prized in China for their medicinal properties and earthy flavor.
For more information about Puer tea, read Preparing Puer Tea.