The schema is the central configuration concept in STG: it defines the fields, sections, screen captures, Panoscrolls, reports, preambles, and overall structure for a record type, and it drives both how the bots capture and how the PDF renders. Crucially, schemas aren't flat — they support complex types, including nested and repeated structures, and the nesting can include arrays of complex types. That matters because real business records are hierarchical (an order with line items, an employee with a history of roles), and a flat model would flatten the meaning out of them.