Basic Concept of an ORM

It will generate four files for an entity= Table

say for example - Employee

1) employee.php (over ride or define some new methods (getter setter or others) on your own= custom code)
2) baseEmployee.php (avoid touching it, as these are the files automatically generated by ORM)

These files are basically to deal with Object level things

3) employeePeer.php (here you can override the basic query for an object )
4) baseEmployeePeer.php () (The basic CRUD queries are written here- automatically generated by Propel)