What is Bolt, in the context of Slack development?

Bolt is Slack's higher-level application framework for building Slack apps with common platform patterns already organized for developers. Rather than manually wiring every incoming event, interaction, Web API request, acknowledgment, and middleware concern, Bolt provides listener registration, context injection, utilities such as `say()` and `ack()`, and convenient access to Slack API clients. Official Bolt implementations are available for JavaScript, Python, and Java, each built around Slack's corresponding SDK capabilities. Bolt is not a message database, a Marketplace billing system, or a CSS framework for Block Kit. Block Kit is Slack's UI composition system, while Bolt is application-development infrastructure. Therefore, B accurately describes Bolt as a higher-level framework that simplifies event handling, interactivity, and calls to Slack platform APIs.