If you want to make money online you will need to sign up for Google’s advertising program Adsense. This is definitely not the only way to make money online but it is a proven earner and can add up quickly.
Advertisers bid against each other for keywords to have their ads displayed on relevant pages found by the search engine. Each time someone clicks on an ad, the advertiser is charged a fee by google. Google keeps most but passes on a percentage (undisclosed) to the owner of the site the ad was placed on. This is how you earn money from Google ads. The more competition a keyword has the higher it pays – but there is also more competition amongst publishers to host the ads. It is extremely difficult to get your page found on high paying topics due to the sheer volume of competing sites.