Havana Twists as well as many other African Hair Braiding styles have become very popular as of late and here's a post to clear up what styles you're getting/doing and what makes them different.
OKAY, Here’s a little breakdown.
This photo is of the Marley Twist hairstyle. Marley Twists are similar to Senegalese Twists, braided at the root, except using Marley Braid Hair(which is coarse synthetic/kanekalon hair, more coarse than afro-kinky hair.)
Now this photo is of the Havana Twist hairstyle. Havana Twists are large shoulder length twists which are twisted at the root for a natural look. There is a specific blend of hair for this style which is less kinky than Marley Braid hair and Afro Kinky hair but thicker/fluffier than 100% kanekalon jumbo braid(the hair used for box braids).
Of course there are many other twists like Senegalese Twists, Kinky, Yarn, Nubian, and more. Check them all out as well as various styles of braids, plenty of hairspiration and on http://iloveboxbraids.tumblr.com/ Feel free to ask any question :)