A question asked by one of my coworkers (and you all thought I just answered social media, opensource, or database questions, right? LOL)
Q: How does a phone text to email? Does the computer have to have anything magic?
A: You can text to any email system. It's the phone that has the magic. Each texting phone (which is just about every cell phone except for a few REALLY old ones) has an email address attached to the phone number, so it's essentially email to email. SMS (short message service) = texting, which is based on really old GSM (Global System Messaging) which was back with early cells. It is also limited to 140 characters, which is probably one reason twitter limits to 140 characters. Smart phones actually give you the capability of doing straight email via a web browser or mobile device, so no character limits on those, unless you are texting. ;-)
... I realize this is a really basic answer and it's all a little more complicated than that, but that answered the question. ;-)