Tea is a specific plant called Camellia Sinensis and its leaf is tea. Tea is often blended with other ingredients like herbs and is called "tea" as well. It's kind of a half tea. Purely herbal drinks and fruit infusions are called tea even when there is not a tea leaf in it.
The reason for this confusion is because like real tea these other "teas" are steeped in hot water. Its almost as if anything that is steeped in hot water is called tea. I don't care much about the semantics, but I just wanted to clear the air. So now go enjoy your tea or your "tea".
All tea is good.