Please explain me on 1:18:33 time in the video

#1

please explain me on 1:18:33 time in the video
what is done ( ) function defined and how it is not stopping
js code to move further even when written code is synchronous

#2

in live lecture of 2020 Topic DOM OPERATIONS

#3

please tell me i am bit confused

#4

sorry time is 1 : 33 :48