Javascript in Unity is real javascript?

I’m starting to use Unity and I don’t know if use C# or Javascript.

My question is… Javascript in Unity is real javascript or is “unity script”?

If I use C# I can use the same code in Unity and in my linux server, through Mono, but if javascript for unity isn’t the same for the server, I will chose C#.

Javascript in Unity is not real Javascript. It is more like ActionScript. It bears some resemblance to real Javascript but has major fundamental differences. C# is the same c# everywhere.