Are these majors similar?

Hello. I wanted to know if a major in health science is similar to a major in public health. I was planning to major in public health but I want to know what’s the difference between the two. People have been telling me that they are similar but I don’t know why. Please reply. Thanks in advance!

Google is your friend. Yes, these are just different terms for the same thing.
http://www.publichealthonline.org/health-sciences/