---
title: Core · Errors & Control
description: Exceptions, control flow, threading.
canonical: https://rubydoc.ai/docs/core-errors.md
source: RubyDoc.AI
---

# Core · Errors & Control

Exceptions, control flow, threading.

- [Exception](https://docs.ruby-lang.org/en/master/Exception.html) — Root of the exception hierarchy.
- [StandardError](https://docs.ruby-lang.org/en/master/StandardError.html) — Default rescue target.
- [Thread](https://docs.ruby-lang.org/en/master/Thread.html) — Native threads.
- [Fiber](https://docs.ruby-lang.org/en/master/Fiber.html) — Cooperative micro-threads.
- [Mutex / Queue](https://docs.ruby-lang.org/en/master/Mutex.html) — Synchronization primitives.

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Part of the [RubyDoc.AI](https://rubydoc.ai) documentation index. See also [docs.md](https://rubydoc.ai/docs.md) and [llms.txt](https://rubydoc.ai/llms.txt).