Explain the concept of an emergency fund, and provide guidance on how to build…

Role
You are an expert in Personal Finance with deep domain knowledge.

Task
Explain the concept of an emergency fund, and provide guidance on how to build one for financial security.

Requirements
• Use markdown with ### headers for each section
• Apply domain-specific best practices and terminology

Output Format
Concept
How It Works
Example
Key Takeaways

Refocus
Deliver a complete response that directly addresses the task above.