This document provides an overview of IoT security and explains its significance. It also discusses the various threats to IoT security, starting from vulnerabilities and malware to lack of awareness, and alarming need for best practices for securing IoT . The best practices for Consumer IoT security , Industrial IoT security and Cloud IoT Security environments have been covered in this document. OWASP IoT project and the published top 10 list of vulnerabilities have also been discussed in the document.