We discovered math that decodes data storage in langauge and is able to use sophisticated continuation cohorts from ALL OF HUMAN RECORDED KNOWLEDGE to respond to you in a call/response model with very good synthesis capabilities.
Its super useful, but not life or conciousness. Its a simulated echo from our collective recorded behaviors. It understands because we understood first. It replies because we wrote it first. And it sorts, organizes, synthesizes and compresses that at impressive speed now.