PPC = pay-per-click

PPC is an advertising program where an advertiser buys keywords that will display his ad in a search engine when someone uses those keywords as search terms. As the term suggests, advertisers pay only when someone actually clicks on their ad.

All major search engines have PPC services. Google calls theirs Adwords. You also have the option of displaying your ads on sites that place Adwords advertisement on their site. This is the publisher program they call AdSense. Google pays a portion of the generated advertising revenue to the site's owner for every click that comes from that site.

The two terms should not be interchanged as it leads to confusion, not to mention technically wrong. You use Adwords and PPC in general to create and pay for advertisement to promote your products. You use Adsense to show those ads on your site and generate revenue from it. Saying "My Adsense keywords are all showing a quality score of one" is wrong because Adsense has no such thing as a quality score. Adwords does.

Google Adsense may be one of the fastest and ways to monetize traffic to your website if you have products or services to sell or simply to provide free content to your visitors.

In other words, Google AdSense enables website operators Placer code on their site that connects to the server Google ad content database and extract relevant keywords advertising web pages. The webmaster is paid a percentage of the tax that Google receives from the advertiser each time a visitor clicks on an ad. There is no charge for the webmaster to participate in AdSense. All costs are covered by the advertiser participating in AdSense sister called Adwords.

Google sends digital "robots" that use proprietary algorithms to analyze the Web page host and analyze the content in an effort to determine what keywords are relevant. It reports its findings to the Google ad server that serves ads relevant to those keywords. Given that the whole process is automated, the ad robots "do a pretty good job to get the content of advertising right most of the time.