Sonic is like what A&W was back in the 60's-70's: a "drive-in"
where you can have carhops on skates bring your meals to your car;
you can also do "walk-up", or in some locations, eat inside....
They're based out of Oklahoma City, and they have breakfast
("pancake & sausage on a stick"), lunch/dinner, and lots of
fountain drinks (cherry limeades

, milkshakes, etc.).
In Dothan, AL, near where I live, they have a location inside
the mall - whether this is a test, since nearly all their locations
are outdoors, remains to be seen....