Ladies and Gents. Google has two advertizing tools namely :Adsense and Adwords; both are operated on ppc. The adsense is the tool for you to display ads on your web/blog to make money for yourself, based on number of clicks and page views. Adwords is the marketing tool for Google to make money. When you want to advertize your business online, you go through adwords tool. To subscribe for adword, you need to have a Gmail account and find the apps within your account settings; it requires a credit or debit card to make the requisite payment and also to register your card with Google. After that, you need to set your keywords that are suitable for what you want to advertize; to do that you must consider the traffic worth of the keywords. And after that, you now add your credit card information and your ads will start rolling. Your ads will show up on search engine result page, at the top and by the side of your free emails, also if you have web/blog you can get adsense code which is invariably adword and place it on your page for money making. That is why we are given free email addresses. Cheers.