Why are there so many processes running?
Solution 1:
You are seeing threads. While in htop, press F2 for options then select "Display Options". Check the box for "Hide userland threads" and/or try some of the options in htop like "display threads in a different color"
You may also want to turn on the PPID (parent process id) column. Then you'll be able to tell that all of the threads likely list the same parent process.