Okinawa soba is a local specialty of Okinawa prefecture, which has slightly different history and culture than other prefectures. Soba noodle is usually made from buckwheat(soba is buckwheat in Japanese) but Okinawa soba use flour instead of buckwheat. In Okinawa, soba means Okinawa soba(other prefectures are soba means buckwheat noodle).
The process of making the noodle is same as ramen noodle but the difference is the thickness. Ramen noodle is thin but Okinawa soba noodle is thick. Therefore the texture is much like udon noodle than ramen noodle. Okinawa soba usually comes with soki; Okinawan style spare ribs.
If you are not visiting Okinawa, but if you like noodles, visit any Okinawan restaurant or diner outside of Okinawa. Okinawan restaurant or diner can be found easily especially in metropolitan area. Please be aware that Okinawan meals have distinctive names due to Okinawan dialect is far from standard Japanese.