The Law of Attraction is the metaphysical ideal that what you focus on comes into your life. The Secret, written by Rhonda Byrne, is based on this same principle. If you focus on the positive, positive things will come your way. What you think about comes to you whether you want it to or not. Once you understand the Law of Attraction you will start to notice that what you think about appears your life.
Here are some articles to give you a better understanding of the Law of Attraction. I also included examples of using positive words in everyday life.