Boolean

Boolean has exactly two values: true and false.

local ready: Boolean = true
local finished = false
local shouldRun = ready and not finished

and, or, and not accept only booleans. and and or short-circuit, so an unnecessary right-hand expression does not run.

Every if, elseif, while, and until condition must be Boolean:

if ready then
    print("ready")
else
    print("waiting")
end

Booleans support == and ~=. They can be formatted explicitly with String(ready) or directly inside a backtick string such as `ready={ready}`.