Handles vs Threads vs Processes
Since the StackOverflow answer is so abstract, and OS agnostic as to be useless to the ops specific question, I am posting a Windows specific answer.
A Process is a isolated memory structure which supports an application in OS hardware and software. A Windows Process contains 1 or more Threads. https://en.wikipedia.org/wiki/Process_%28computing%29
A Thread is a stream of sequential machine-code instructions that the processor executes. With the exception of Interrupts, Any time the CPU runs an Instruction on behalf of an application, it does so because a thread contained it. Threads within a process may access the processes memory (to the extent that the specific operation on the memory element is "thread-safe" and doesn't present unreconciled concurrency issues when more than one thread is run simultaneously). An Application may speed its operation by using multiple threads, each performing an isolated task by running their stream of instructions through a different CPU Execution unit (CPU/core/virtual core) simultaneously. https://en.wikipedia.org/wiki/Thread_%28computing%29
A Handle is a logical association with a shared resource like a file, Window, memory location, etc. When a thread opens a file, it establishes a "handle" to the file, and internally it acts like a "name" for that instance of the file. Handles are used to link to transitory or environmental resources outside the processes memory structure. A handle leak is a type of software issue that can in extreme cases, destabilize a system. It is caused by a program requesting a handle to a resource, and failing to deallocate it when the program is done with the resource. Based on your number however, I see nothing wrong there. https://en.wikipedia.org/wiki/Handle_%28computing%29