delay() uses milliseconds. 1 second --- delay(1000)
But you don't want to use delay(), it ties the processor up completely.
but all of the examples are a repeating scenario
Your repeating scenario is the Arduino keeping an eye on those buttons via RC. Using delay() defeats that purpose.
The examples are to show how to have something change state (blinking led changes between on and off states) based on time passed even as the MCU is able to do other things, like watch for user input or run motors.