One of the reasons JavaScript has the word "script" in it is that as a programming language, the
vocabulary of the core language is compact compared to full-fledged programming languages. If you
already program in Java or C, you actually have to unlearn some concepts that had been beaten into
you. For example, JavaScript is a loosely typed language, which means that a variable doesn't care if
it's holding a string, a number, or a reference to an object; the same variable can even change what type
of data it holds while a script runs.
The other part of JavaScript implementation in browsers that makes it easier to learn is that most of the
objects you script are pre-defined for the author, and they largely represent physical things you can see
on a page: a text box, an image, and so on. It's easier to say, "OK, these are the things I'm working with
and I'll use scripting to make them do such and such," instead of having to dream up the user interface,
conceive of and code objects, and handle the interaction between objects and users. With scripting, you
tend to write a _lot_ less code.