Position property in div tag

Question

When we are​ setting the position for div tag contain then when we are setting its value according to our monitor but what if the user have a small sized monitor.

Answer 1

we using media queries to set new position for other viewport sizes

Answer 2

but what's that

Answer 3

https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries/Using_media_queries

Answer 4

I used that also but I don't understand that the absolute relative and fixed means