What is MetaSpace? How does it differ from PermGen?

MetaSpace (Java 8+) replaced the PermGen (Permanent Generation) from earlier versions.

Key Differences:

1. Memory Type: PermGen was part of the JVM Heap (contiguous memory). MetaSpace uses Native Memory (RAM outside the heap).
2. Sizing: PermGen had a fixed max size (-XX:MaxPermSize), often leading to java.lang.OutOfMemoryError: PermGen space. MetaSpace can grow dynamically based on available system memory.
3. Management: Garbage collection of classes is more efficient in MetaSpace.
4. Args: PermGen used -XX:PermSize; MetaSpace uses -XX:MetaspaceSize.