I don't understand iMessage?

What's the difference between iMessage, SMS, and MMS? Okay if I'm texting a iphone user and I use iMessage and they can't use iMessage will they still get the text? And if I can't use iMessage and they are using it and they sent me a text will I get it? Or no? Because I was texting this girl and I sent her a iMessage and then I turned off my data and then I turned it back on in about 4 hours and immediately I got a reply back from her. And when I say turn off iMessage will anybody get my texts? Will somebody explain all this to me?

Sprint 14-Day Exchange Policy?

I just got an iPhone 5c but I want to exchange it for the 5s. According Sprint's web site, the policy states that I have 14 days to exchange my phone starting the day it was activated. But it doesn't say if I have to also return the container, and headphones, and apple stickers it came with. Does anyone know how this works? Do I have to return everything, like that way I bought it? And let's say, for instance, I lost the case or the headphones, what would happen?

Best website to unlock an iPhone 4?

I have found two websites that will unlock my iPhone for free.

phoneunlock.me

iphonegeeks.us

Does it matter which one I use or does anybody have another site that is better?

Can I exchange my Iphone at a Apple store for a different color?

I got the Iphone 5s for christmas but it is the gold. I would prefer the black, I went to Telus, where we got it from and they won't exchange Iphones. Do you know if I can go into an apple store and get a black one? Maybe a re-stocking fee? Or is it not an option

How to revoke someone's access to my twitter?

I used my friend's iphone to log onto my twitter one day and she never logged off. It wouldn't be a problem if she didn't unfollow people and delete tweets. I know that you can't revoke iphone access from online but she won't delete my account so I have no idea what to do.

Added (1). Oh and I've tried changing my password but that didn't do anything

Added (2). if you didn't read what i JUST SAID, changing your password doesn't do anything it stays logged on to every device

I can't send or receive text messages?

I have an iPhone 4, iMessages send without a problem but randomly last night my messages stopped sending and I wasn't able to receive them either although it says they are sent from my phone and it says they are sent from other people's phones. I have tried updating my phone, my computer, resetting my phone, doing a hard reset, resetting the network settings, turning on and off airplane mode, and turning on and off do not disturb (these were all suggestions). I can call anyone and receive calls even if they do not have an iPhone. I can't figure this out please help!

Switching an iPhone 4 from Verizon to T-mobile?

I'm on T-mobile. I'm planning on buying a Verizon iPhone 4 tomorrow because I've heard all I would need to do is put my T-mobile sim card into the phone. Is this true? I want to be sure it'll work before I buy it.

If that won't work, what do I need to do? Do I need to jailbreak it? How do I jailbreak it if I need to?

Thanks in advance!

Added (1). Is unlocking the same thing as jailbreaking? Or are they two different things?

Moving to New Zealand next year-are there any main differences?

Hi, I'm 14 (eighth grade) and my mom's job just got moved to Auckland, and I'm moving there at the end of the year. I'm excited but nervous at the same time because all of my friends and family live in the US! But I do have some questions about New Zealand.

--Is it like Australia? Lol I know you might get offended by that but I've seen Australian movies, tv shows, met the people, so I know a bit about that country. Is NZ very similar?

--Is the technology the same? (Will I be able to use my MacBook and iPhone?)

--Are the kids like the US kids, or are they into totally different stuff?

--What is the school year like?

--Will people think it's totally weird that I'm American? Are there any there, and do they hate the US?

--Does everyone speak English? I saw on Wikipedia that there are 'Mauri' people, so.

-Is the New Zealand money way different?

-What are the primary differences between American and New Zealand culture?