What is Enalapril ?

I have heard a lot about Enalapril, but i am not sure exactly for what this medicine is used for. I want to know how does Enalapril works and what are the side effects of this medicine if this medicine has any, i want to know it? Approximately how much does it cost. I want to know everything about Enalapril, If anyone knows about it please share it with me. Thanks.