I would like to share a tips with you, if you could just type "What is______________" "UV filter", "CPL filter", "IR filter" in Google Search.
you will have all the answers you are looking for instantly, faster then you posting this thread.
Try it, it works every time, and it is free, beside, you will not get slam by others, sometime, if I'm not in a good mood, I may post a photo of spoon feeding in a thread like this.