Soba refers to noodles made with buckwheat and to dishes made with these noodles. They became popular as a "fast food" during the Edo Period (1603-1868).
The two main styles of eating soba are zaru-soba, where noodles are served on baskets and dipped into a sauce in another container, and soba noodles served in soup with various toppings.
Soba is made of buckwheat flour, water and a little salt, but many restaurants' noodles also include wheat flour. Soba that is solely made with buckwheat flour is specified as "十割” (ju-wari, meaning 100%) soba. Buckwheat is a potential allergen.