In session the first thing that you see is Form. Form is used as an interface between user and table where his data id stored.Form is used to get input
Ans This is the most basic question that why we create session. See data is stored in tables, so to manipulate the data which is stored in tables we use sessions. Session is used to add data into tables, we can delete the data from tables. For these purpose we have different kinds of session or we can say types of session:
1)Single occurrence(with one main table): Form is used to display only one record of a table.This kind of form is used mainly in maintain and display session.
2)Multi-occurrence(with one main table): Form displays more than one record of a table.This kind of form is used mainly in maintain and display session.
3)Multi-occurrence (with one main table) having some common filed: It is very similar to type-2 form but in this form type there will be some common field(s) to which all the records will belong. For example Maintain Production BOM session.
4)Single occuerrence(Without main table): In this type of form data daoes not come from single table but it comes from more than table.Print session is an example of this.