Link is the main character of The Legend of Zelda series and despite him being around for over 30 years, we know very little about him. Part of this is because he doesn't really talk, so he doesn't really have a way to communicate or express anything about himself! Miyamoto has said that this is because he wants the player to more or less feel like they are Link and having a speaking protagonist would break this illusion. Not only that but Miyamoto has also confirmed that there are multiple Links throughout time, so he wouldn't really have a definitive backstory anyways.
Regardless, Miyamoto and his team do know some information about the mysterious green tunic-wearing character, they just choose to keep most of it secret. Speaking with Game Informer, Miyamoto confirmed some interesting details about Hyrule's greatest warrior. One of these things was Link's full name which is similar to Mario's: Link Link. Yes, it's just his first name for both names.
It's unclear if he was joking because he's previously stated Mario and Luigi don't really have last names, despite the terrible movie stating their last names are Mario (hence them being the Mario brothers). At the moment, we will take this as official confirmation of him being Link Link!
Another interesting statement said by Miyamoto is that he's not human despite Hyrule being on Earth… what?! Honestly, we have no idea how to interpret this. The reveal trailer of Super Mario Odyssey has made people question if Mario is human and if he's even from our Earth. Nintendo's got a very interesting, unique world in their hands. With the confirmation of Hyrule being on Earth, it also brings me wonder if Mario could eventually travel there during his time in our world in Super Mario Odyssey.
One other thing was confirmed, Link will not speak a full sentence (and probably not at all) in The Legend of Zelda: Breath of the Wild despite the game having a fully voiced cast of characters. This is, as previously mentioned, to help maintain the illusion of Link being an in-game representation of the player.
The Legend of Zelda: Breath of the Wild will release for Nintendo Switch and Wii U on March 3rd. One man was granted the chance to play the long-awaited game before he passed away, you can click here to read the heartbreaking story.