Evil Eye

Would you please explain the concept of "Ain Hara" in judaism? I know it is mentioned in Gemara and Shulhan Aruch but i could not find the explanation of its nature and how for a jew to relate to it.

One should know there is Ain Hara that exists in the world, but not everything bad that happens is because of it, especially by a Jewish person who can change things by praying and avoid being harmed by Ain Hara. Moreover, it says that whoever believes in Ain Hara can be harmed by it, and whoever doesn't has nothing to worry about, it all depends on the significance one gives it. Hence, one should not worry, since there is none other than He, one can rely on Hashem that he won't be hurt if he isn't supposed to, and, of course, we need to ask for help in our prayers. Rabbi Ro'i Margalit