In addition to Tanmay's reply - on types of search ads.
I guess, the 'advertisement ads' that you amy be referring to are shopping ads (Google Product listing ads PLA's) in Search Advertising. For E.g: Look at a Search term ' Blue tie' and you'll end up with images & the price and their avialability.
Display ads are displayed on the site.
but here, you had to search for 'blue tie' to get to the images.