It is radically different from traditional ways of teaching language. There are no textbooks, and often there are no tables in the classroom. The idea behind this method is to help students learn a language exactly the way they learned their first language – naturally. Our brains are equipped with the ability to acquire a language, and if the circumstances are right, learning will happen effortlessly.
The teacher’s role, then, is to provide those circumstances: A LOT of input in the target language, specifically Comprehensible Input (CI, see Krashen) and lots of repetition. Students are not expected to produce the language until they feel ready to do so, but it doesn’t mean that they are not active participants in the class; they may not have to speak but they are required to pay attention, react and answer questions by gestures, expressions or any other way. Grammar rules are not taught as rules but are still acquired naturally through input and repetition, just like when we acquire the grammar of our first language without even knowing what a verb or a clause is.
Another important aspect of TPRS is that it is FUN. Without the prefixed tracks of a textbook, the teacher follows the students’ interests, talks about the students and makes them active participants in building stories together so that the class will always be interesting and engaging.
Here are some great resources for learning more about this awesome teaching method:
Watch the awesome Terry Waltz explaining TPRS
Check out Blaine Ray's blog about TPRS