What is Rake?

What is Rake? I don't understand what the use of it is. Say I have
already made a RoR app, It's all done and ready to go. I can just so
script/server, and boom its running. What is the use of Rake? I
understand that it's to "deploy" the application but what does that
mean?

That's not really what rake is (were you thinking of capistrano?).
rake is a fairly general purpose tool, from the rake home page

"This package contains Rake, a simple ruby build program with
capabilities similar to make.
Rake has the following features:
Rakefiles (rake‘s version of Makefiles) are completely defined in
standard Ruby syntax. No XML files to edit. No quirky Makefile syntax
to worry about (is that a tab or a space?)
Users can specify tasks with prerequisites.
Rake supports rule patterns to synthesize implicit tasks.
Flexible FileLists that act like arrays but know about manipulating
file names and paths.
A library of prepackaged tasks to make building rakefiles easier.
"

rails comes with a bunch of tasks you may find useful while working on
a rails app (type rake -T from your rails app to see them) and of
course you can write your own

Fred

What is Rake? I don't understand what the use of it is. Say I have
already made a RoR app, It's all done and ready to go.

Wow, you made an RoR app without using rake.
You must share with us on how did you do the following without rake.

1) create the databases for the environments (ie dev,test and/or prod)
2) list all your routes
3) prepopulate your database table contents (ie. fact data)

I can just so
script/server, and boom its running.

Yeah, magic isn't it? That's mongrel which is the default application
to run your rails codes.
Other options are passenger and thin.

What is the use of Rake? I

understand that it's to "deploy" the application but what does that
mean?

What do you mean by deploy? Rake is somewhat like make. It does not
fully deploy. As per Frederick Cheung, I think you meant Capistrano or
something of that nature.
Find a rails book or a tute and start reading.

Wow, you made an RoR app without using rake.
You must share with us on how did you do the following without rake.

1) create the databases for the environments (ie dev,test and/or prod)

First time I used Rails I created a DB in phpMyAdmin and manually
added the fields...

2) list all your routes

Back then, I hadn't grasped routes (still find them slippery little
buggers even now)

3) prepopulate your database table contents (ie. fact data)

I did, however, discover the console early on, and (mis)used it
happily for a few months.

Ease up on the sarcasm when someone asks a perfectly legitimate
question.... as if you understood everything in one blinding flash
when you first dabbled with Rails...

Ease up on the sarcasm when someone asks a perfectly legitimate

question… as if you understood everything in one blinding flash

when you first dabbled with Rails…

Agree but a lot of us here prolly did the hardyards of reading up before asking.

This is true.
Preeti, the books do cover this quite well. But here's a blog post
that does it too:
http://jasonseifer.com/2010/04/06/rake-tutorial

And as lots would recommend, so would I, get yourself a copy of "Agile
Web Development With Rails", and bury yourself in it for a couple of
days.

http://pragprog.com/titles/rails3/agile-web-development-with-rails-third-edition