Online advertising is when companies place ads on websites and other online services to try and get people to buy their products and services. Companies create ads that are designed to draw people's attention and make them interested in learning more about a product or service. These ads often contain pictures, videos, and information about what the company has to offer. When you click on the ad, you're taken to the company's website to learn more. By doing this, businesses hope that you will buy whatever it is they're advertising.