This document provides an overview and definitions related to digital identity and authentication. It discusses identity, authentication, tokens, and standards like NIST 800-63-1. Passwords and threats like cracking are covered. It also summarizes one-time password (OTP) technologies like time-based, event-based, and out-of-band OTP as well as standards like HOTP, TOTP, and OCRA. The document aims to introduce concepts and topics around digital identity and strong authentication.