Thread Dump: When we trigger a thread dump on an application server, all active thread informations will be deserted into file which is called as thread dump. Here, we can get information about thread like active thread, hung thread, dead lock, runnable and inactive thread info.
Command: kill -3 PID (Process Id)
Heap Dump: its snap shot of our JVM's heap memory, so here we can have all active java objects and their activities which object actioning what and how much memory it is occupy.