Definition from Gartner
“Context-enriched services are those that combine situational and environmental information with other information to proactively offer enriched, situation-aware and usable content, functions and experiences. The term denotes services and APIs that use information about the user to optionally and implicitly fine-tune the software action with better situational awareness. Such services can proactively push content to the user at the moment of need, or suggest products and services that are most attractive to the user at a specific time.”
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