Mac

"Is it a problem?"

Doubtful? I have 204 active background processes running most of the time and I don't perceive anything going slow.

Background processes will include all sorts of things that won't be apparent by simply looking at your desktop. Assuming you can drive a car a simple analogy would be you turning the ignition key to start the car's motor. All you know is the engine is running. But what's actually happening is a fairly large number of independent, yet related, actions all combining together to make your motor run.

There are many reasons why your computer might be running slowly. Some runaway or unwanted background processes might cause it although it's difficult to know without any more details. Then again filling up your hard drive may also cause a perceived slow-down. Ditto for launching too many applications, or trying to use applications that are too new or too powerful for your mac depending on how much memory (RAM or hard drive) you have.

Whomever said you had things running in the background which was slowing down your computer should qualify what they meant in more detail. If this person is a reliable computer technician ask them to explain it clearly and if possible get them to look at your mac. Finally if you're not happy take your mac to your nearest Apple Store/Genius Bar/Apple Authorised Repair Specialist and get them to have a look at it as well.