What determines the speed at which your computer performs tasks?

Well there is a couple of things that can go with this subject trust me  i know im a computer geek

well first things first sometimes of what you have downloaded on your computer or loaded onto the drive will sometimes make the computer preform tasks very slowly 

next is a lot of music or documents that can be uploaded or pictures that are uploaded onto the computer when you have those it can cause your electronic devices to run slow also and if you view certain things it can cause viruses on the computer and cause the device to act up and run very slow and it can crash your devices 

I HOPE THAT I HELPED YOU A LOT THANKS SINCERELY ..