Not only is this a great tool for general study of facts and concepts, but it, also, works well for learning languages.
Starting off, a student can easily Sign-up and Sign-in via their school Gmail account. Making it very easy and secure for a student to register for an account. Once started, a student can create a data bank of terms and definitions grouped in what Quizlet calls study sets. Below is a video demo of using Quizlet.