what is the differences between air purifier and air cleanser ?
i ve just went to the doctor regarding my sinusitis; and he said i should buy an air cleaner…however there is a lot of models said that it is an air purifier….i just wondering what is the difference between them ? and which one is better to reduce my sinusitis (which has become polip) problem

Air cleaners and purifyers are about the same. You should look for something with a HEPA filter which is the most effective at removing a wide range of things from the air in a room. Make sure you buy one of sufficient size for the room you are going to use it in most.