You can get email notifications any time that Google finds new results on a topic you’re interested in. For example, you could get updates about a product you like, find out when people post content about you on the web, or keep up with news stories. – How Google Alerts Work
You use Google Alerts the same way you use a normal search engine by entering a search term. You then enter your email address so that results will be emailed to you. By clicking on the Show options link you can configure the frequency of these emails, limit the sources of information, choose language and region, and choose whether you want to receive all results or only the best ones. Finally, simply wait for the alerts to start coming to your email in accordance to the options you set.