The document discusses an EFL teaching book written by Paul Nation called "What Should Every EFL Teacher Know?". It provides an overview of the book's contents which includes topics and a walkthrough. Nation wrote the book because other similar books were missing what he felt was important. He also wrote an accompanying ESL book after realizing ESL teachers needed different guidance. While he thought the ESL book could just copy the EFL book, they ended up being very different, showing how writing can be a learning process.