Can we use WRITE statements in screen fields?if not how is data transferred from field data to screen fields? ABAP Module Programming

-We cannot write field data to the screen using the WRITE statement.The system instead transfers data by comparing screen fields names with ABAP/4 variable names.If both names are the same,it
transfers screen fields values to ABAP/4 programs fields and Vice Versa.This happens immediately after displaying the screen.