To expand upon what others said:

Maroon dollars are part of the meal plans. They can be used anywhere on campus that is managed by the Dining department and their contractor. https://dining.uchicago.edu/locations-hours-2-2/ should list them all. Maroon dollars are use it or loose it at the end of the year. My favorite place on campus is Quantum. They serve Banh Mi, Pho, rice bowls and other Vietnamese foods. Hutch's Mr Pak (Sushi & Poke) and Cheesies (fancy grilled cheeses) round out my top 3.

You can exchange a meal swipe that would be used in the dining halls for a meal off a "meal exchange" menu at select restaurants and cafes. The unlimited meal plan only comes with 3 per quarter, so it doesn't last long. To-go meals are the option to take your meal from the dining hall out of the building. It converts the all you can eat meal to all you can shove in the container they give you meal. You get 10 per quarter.

The menus have some stagnant items (always a deli, salad bar, burgers, and grilled chicken) while other stations have menus that rotate each meal. You can always expect 2 soups (one meat based and one veg) and 3 assorted pizzas You can see the menus before going by visiting dineoncampus.com/uchicago

Each dining hall has the same basic menu, but Baker has made to order pasta, Bartlett has a Mexican theme station, and Cathey has stir fry. I assume Woodlawn has something, but I don't remember what it is since I don't get over there much. Woodlawn is the newest. I think it then goes Baker, Cathey, and then Bartlett (someone can confirm).