When I open Java Perspective, I see diffferent windows on the screen
A windows in the centre, where I can write code
A window in the left, where I can see Fast View
A window below main centre window, where I can see Debug, Console etc
There are two windows in column right of centre window. Top window in this column is Task List and bottom window in this column is Outline.
What are all these windows known as ? As these windows can contain different information thna one described in here.
Those windows are knows as views. You can see a list of all the views available by going to Window | Show Views | Other.
A "perspective" in Eclipse is simply a predefined set of views. Besides the perspectives that come with Eclipse you can create your own. Look under Help | Help Contents, the Workbench User Guide | Concepts topic will tell you about perspectives and views.
To be a little pedantic, but possibly head off some confusion: the one in which you type your code is not a view, it's an editor. The two are different. Editors are always in that center position -- you can't have a set of tabs where one tab is an editor an another tab is a view. If you ever get into development for the Eclipse platform, you'll learn that they're two separate animals.
Hmmm. Now this is interesting. I was pretty sure that when I last worked on plug-ins, an Editor was a species of View. However, I see that there is no explicit menu for source code editing (probably because there's no attached resource for an uninitalized editor).
Also, while the editor doesn't seem to want to be moved on the Galileo release, you can move it indirectly by relocating other views around it.
An IDE is no substitute for an Intelligent Developer.