Concurrency (Parallel Processing is part of it)

Clojure Thread in Parallel Processing (run on JVM, same as Java threads).

Number of Threads =  Number of CPU cores + 2

Example:
Samsung Galaxy S4 Quad-core CPU => Number of Threads = 4 + 2 = 6 threads

http://www.thattommyhall.com/2014/02/24/concurrency-and-parallelism-in-clojure/