The security labs are documentation and code in the format of hands-on labs to help you learn, measure, and build using architectural best practices. The labs are categorized into levels, where 100 is foundational, 200 is intermediate, 300 is advanced, and 400 is expert. Quests are designed to collate a group of relevant labs and other resources together into a common theme for you to follow and learn.
For more information about security on AWS visit AWS Security and read the AWS Well-Architected Security whitepaper in PDF or online . Also check out https://awssecworkshops.com/ for hands-on workshops, and AWS Training and Certification Learning Library for official security training options.