It’s often translated as “tea ceremony”, but Chado, Chanoyu or the “Way of Tea”, is neither a ceremony nor a ritual, but more a celebration of arts (craft, culinary, etc) and philosophy (particular Zen Buddhism). Or according to Leonard Koren, it’s “an eclectic social art form combining, among other things, the skills of architecture, interior and garden design, flower arranging, painting, food preparation, and performance.”
It originated in China in the 8th century, spread to Japan in the 9th and became an art sometime around the 12th century, but it wasn’t until this past century that the way of tea has become accessible (in Japan it’s often studied like home ec or in a college club).
The lure may be partly in the brew- tea has always been used for health-, but Christy Bartlett of the San Francisco Urasenke Foundation explains that following the form (she compares it to the practice of music) helps one to find intense focus in the moment.