IDX is a technology term for Internet data exchange with allows a real estate website to have MLS data on it which makes the website searchable by the public.
IDX is built on the concept of Broker Reciprocity which is the idea that any broker that opts into IDX grants the right to all other participants to display his listings and receives the right to display theirs.
IDX exists to help real estate agents market listings, attract leads, and close more sales. By displaying listings online, agents can reach a larger audience and better match available homes with prospective buyers.
MORMLS offers an IDX feed for brokers and agents to use on their websites so the site can be searchable by the public.