Walk me through the four core OmniStudio building blocks and explain how they fit together in a typical implementation.

OmniStudio separates presentation, guided interaction, data access and server-side orchestration into four component families. A well-designed implementation uses each for what it is good at rather than pushing logic into whichever component the developer knows best.

1. FlexCards are the display layer. They render a summary of a record or dataset, expose actions, and act as the launch point for deeper interactions. They are read-oriented and support conditional states so the same card looks different depending on the data.
2. OmniScripts are the guided interaction layer. They present a multi-step form, validate input, call server-side actions, and produce a data JSON that represents everything the user entered and everything the script retrieved.
3. Data Mappers (formerly DataRaptors) are the data access layer — declarative read, transform and write definitions that move data between Salesforce and JSON without Apex.
4. Integration Procedures are the server-side orchestration layer. They sequence Data Mappers, external calls and Apex into a single server round trip, with conditional execution, looping, caching and error handling.
5. A typical flow: a FlexCard on an Account page shows open cases and offers a 'Log a new case' action; that action launches an OmniScript; the OmniScript seeds itself with a Data Mapper Extract, collects input across a few Steps, and on the final Step calls one Integration Procedure that creates the records, calls an external system and returns a confirmation.