The latest versions of Mozilla Firefox show ads on the icons of a new tab. If you're one of those who can not stand it, you can get rid of them easily.
The Mozilla Foundation added these tiles to ads to reduce its revenue dependency on Google, which has been the main source of revenue for many years, due to Google's search for the default search engine in the browser Firefox. The Mozilla Foundation, however, chose not to renew its partnership with the company, and as an alternative source of revenue, decided to place ads on each new tab page.
Mozilla claims that these new ad slots do not jeopardize your privacy, that is, they are not used to track your activity or collect third-party information. However, some of you may not want to have them on every new tab you open.
To get rid of your ads, do the following:
Open a new tab in Firefox
Click on the gray gear icon in the upper right corner to see its menu and select the "Classic" option.
You're done. With Classic, Firefox will only display webpages from your browsing history on the new tab page. Note that tiles already existing and displaying ads will not be left alone. You should remove them yourself.
Alternatively, instead of the Classic option, you can select "Blank", but your new tabs will appear blank, which makes them less useful.