can someone explain to me what the difference between the terms in the Memory Pool is? JVM - Server Status Tomcat
Those names are different memory areas used by Java Virtual Machine and its Garbage Collector.
The memory model used by JVM differs from one version to another and from one vendor to another. When looking for information you have to know what version of Java you are running.
See e.g. "Understanding the Java Memory Model and Garbage Collection" article from DZone.
Tomcat just displays the names returned by Java via its instrumentation API (java.lang.management.ManagementFactory.getMemoryPoolMXBeans()).
