Object oriented php class simple example

i am beginner on php so now i try to learn object oriented i was goggling i got it some ideas but not clear concept.So i come there.Please any php guru give simple example of how to crate classes and how to call on other php page.

for example

i want two classes one is show name and second one is enter name.First class show name this name come from database and second class put name in database.

Index.php

<form action="checking.php" method="post">
      <input type="text" placeholder="Please enter name">
</form>