What is the OG? Rachel Wisuri December 23, 2021 18:03 Updated The "OG" is The Official Guide to the GRE, written by ETS themselves! :) You can read more about it on our blog post here: Best GRE Prep Books 2021-2022 Related articles Let's Excel at the IELTS (student version) Can I download the lesson videos to my computer? Active Reading Can I download any of the material? (IELTS) How to Ask a Good Question Comments 0 comments Article is closed for comments.