I'm quite new to Node.js but I heard that it's really good. Does it really solve the need of server side scripting? I'm thinking of learning it if I can get goo

I'm quite new to Node.js but I heard that it's really good. Does it really solve the need of server side scripting? I'm thinking of learning it if I can get good justification to. I currently program in PHP for all my websites. Any pointers and comments greatly appreciated. Thanks in advance.