Pause

Pause[n] pauses evaluation for at least n seconds.

Examples

Pause for 2 seconds:

Pause[2]
(* Null - returns after 2 seconds *)

Use Pause in a loop for delayed output:

Do[Print[i]; Pause[0.5], {i, 3}]
(* Prints 1, 2, 3 with 0.5 second delays *)

Please visit the official Wolfram Language Reference for more details.