Root is the term Linux uses for Administrator (Windows). Having Root access means you can remove Bloatware (like Sprint Football, Nascar, Moxier Mail, or basically any app that you don't want that is installed by Sprint but is installed in a "Root Only" section of the phone's OS.

I just Rooted my Moment last night. To do that, I had to Flash the phone with a custom Kernel from SDX. From there, you can manually remove applications from your phone by using a terminal program like Connectbot (available in Android Market).

Here's how I rooted my phone.
1. Downloaded the JoeyKrim 2.0.2 custom Kernel with Recovery.
2. Used the Sprint Updater tool for the CL14 release (the newest tool won't work without a hack) to flash the Custom Kernel to the phone.
3. I then created my own custom ROM from Joey's website. Doing this allowed me to add Live WallPapers (overrated), 3D Gallery (awesome), HQ YouTube (plays High Quality by default), and removed any pre-installed apps like Moxier Mail, Sprint stuff. I then loaded some custom boot images, like the Samsung/Android loading screen, and then the Nexus One Bootloader image (really cool). It then packaged it up into a nice neat .ZIP file which I saved to my SD card.
4. After saving the .ZIP custom ROM to my SD card, I rebooted the phone and launched recovery mode (power down the phone, then press and hold Vol. Down, Talk, End to launch recovery mode). I then chose "Apply .ZIP" and it loaded my custom ROM.

My phone is now fast, and even better than it was before.

 

Without getting into what root is, rooting your phone allows you to interact with all the files in the OS, not just what Samsung/Sprint intended. The main reason people root is to remove/replace some of the apps that Samsung/Sprint put on the phone that most view as unnecessary (AKA bloatware). A good example of this wold be the bejeweled demo which due to very limited play is almost useless. And yes, rooting and removing apps is very easy to do. "Dumping a rom" is not something a casual user will ever do. Usually, it's a way of obtaining code that the mfg doesn't release openly.

 

I have another question about rooting. I am still within my 30 day window. If I root, will that mean I can't return it if I decide to?

 

it voids the warrenty but if you decide to return it all you have to do is reflash the official 2.1 and root would be gone along with any mods you make.

 

Dude! Bumping is bad form, especially when your questions were answered.

 

First, I'm don't use any pre cooked roms, so I may not be the best person to give you an answer. Your first question is answered in the first post of the SDX thread where the rom comes from. No, it won't wipe your data

[Kernel - DE03] joeykrim-SDX - v2.0.3!!! - May 25th 2010

I have never configured the gallery.

This a good thread on what's safe to remove and what isn't.

Ultimate Guide to Removing Apk's and Odex's and Replacement Application Options

I hate when people play thread police so I reluctantly say this, but you're asking questions here that belong either in the root section of this forum or over at SDX.