This document discusses ontology mapping. It begins with an introduction to the semantic web and ontologies. Ontology mapping is important for allowing different ontologies to be aligned and related. There are different types of ontology mapping including alignment, merging, and mapping. The document then surveys some popular ontology mapping techniques including GLUE, PROMPT, and QOM. It evaluates these techniques and discusses their inputs, outputs, and approaches. The document concludes that semantic web research is important for advancing web technologies and realizing the goals of web 3.0. Future work could involve developing new ontology mapping techniques and publishing research on existing mapping methods.