Welcome to AC!
I'm sure once you have a little time to tinker with that Moto G you will find much more to enjoy over what you had with your iPhone 5.
Short answer to rooting and ROMs..
Rooting is unlocking or gaining access to system level or " administrator level " file system access. Basically you can gain access to and can add, delete & modify the /system/ level partition of the device or your Android OS and other important device/system files that are normally locked down to the common user.
What does this do exactly? Well again in short order.. You can then use various programs to delete carrier or OEM bloatware. You can also flash custom ROMs which is basically an independent developer or team of developers have taken the official Android OS and modified it to remove carrier/OEM bloatware and even add various custom mods and tweaks to make your experience better.
Why would someone want to do this? Well running custom ROMs gives you many benefits if your one who likes to live on the wild side sorta speak. You can run early NON OFFICIAL builds of upcoming Android OS that maybe available on another phone but not yet made official for your particular device but the developers have hacked it or built it to work for your device. This is a common reason. Other reasons are to use and gain access to the varying custom mods that are built into many custom ROMs. Things like additional homescreen options, user customizable options like changing your status bar colors, icons, turning things on and off that you normally couldn't, etc... The list of mods grows every day that is incorporated into custom ROMs.
Is it safe? Yes if you take your time and read, research and become familiar with all the terms and programs used to do this. Its not something you run into blindly and then hope for a bail out when you screw something up. Yes this happens many times a day but again its usually from people who rushed the issue and didn't take the time to properly educate themselves with the numerous guides and how to's on how to do it for your specific device.
Does it void you warranty? Yes while your device is in the " rooted " state if you were to take it in for repairs or warranty work the carrier/store has every right to deny you of any such claim. BUT, 99.9% of the time if you've educated yourself you can restore the device back to complete stock and remove all signs of rooting and hacking and then have your device serviced, sold or warranted if need be.
Hope these answers help!
Enjoy the forums and have fun with that Moto G!
Paul
Moderator Team Leader.
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