Why is String immutable in Java?

Strings in Java are immutable because:

1. Security: It prevents accidental or malicious changes (e.g., in passwords or file paths).

2. Thread-Safety: Immutable objects are inherently thread-safe.

3. Caching: Strings are stored in the String Pool for reuse, saving memory.

4. Performance: Immutable objects can be safely shared without copying.

In short, immutability ensures safety, efficiency, and reliability.