- The Permanent Generation memory pool contains permanent class metadata and descriptors information when classes
are loaded
- PermGen space is always reserved for classes and items that are attached to them (i.e., static members)
- PermGem space is contiguous in memory to the Java heap and have the same rounds of Garbage Collection but it is not part of the Java heap
- In JDK8, the PermGen space has been entirely replaced by Metaspace which is no longer contiguous to the Java heap and now exists in native memory