People use these two words as if they mean the same thing. They don't, quite — and picking the wrong one is why someone occasionally leaves hungrier than they expected.
The short version
A smoothie leans fruit-forward and refreshing. A protein shake leans filling. If you want something that tastes like a treat on a hot afternoon, that's a smoothie. If you're replacing a meal you didn't have time to eat, that's a shake.
That's genuinely most of it. The rest is flavour preference.
Pick by the job, not the name
Ask yourself what the drink is doing for you. Cooling you down after work in July? Smoothie. Standing in for breakfast at 6:45 AM? Shake. Something to sip through a long afternoon? That's a third answer — probably a loaded tea.
Ordering gets much easier once you lead with the job instead of the name.
Can't decide?
Say what you're after out loud at the counter — "I want something refreshing" or "I need this to actually hold me over" — and let them steer. That's a faster route to the right cup than reading the board twice.
Or call ahead: (402) 713-0007.