Lunching a satellites has two process, called Launch Period and lunch window.
Lunch period is the specific period between two lunch window.
Since Planets orbit round the sun, sending satellite to any plants required target and we’ll calculated position when it will be easy to lunch the satellite so that it can get to the targeted destination without any obstacle.
So that specific time, it will be easy to successfully Lunch satellite is called lunch window.
That is the space between the first and the second lunch window is reffer
A lunch window is a particular period of time in which it will be easier to place the satellite in the orbit necessary to perform it’s intended function.