SAP ABAP Select-Option Fields LOW-HIGH

Today I am going to answer a question from one of the students in the SAP ABAP Beginners course:

Hi ,
I am little bit not sure about how low and high field work here . when we can set the max or min value that we want to include or exclude in our report using LT,EQ,GT and so on.

Could you explain a little bit about the application of low or high field here ?