This document defines key terms related to eLearning. It provides brief definitions and URLs for 18 terms: adaptive learning, big data, competency-based learning, computer-based training, connectivism, content curation, digital/virtual badges, DIY U, flipped classroom, game-based learning, gamification, hybrid learning, informal learning, MOOCs, OER, personalized learning assessment, student-generated content, synchronous learning, virtual classroom, and learning management system. The definitions are 1-2 sentences and summarize the key aspects of each term.