Could someone explain to me what exactly happens when you read a file?

How does it work when you use a while loop with the condition !fin.eof()? What if my loop contains a statement like fin.get(ch) where ch is of type char?

• How exactly does the pointer move and when is it updated?
• If at the beginning of the file, the pointer points to the 1st element. Does it move over to the second element in the first iteration itself?