jTable is a collection of rows & column. It comes from javax.swing.jTable class.
For inserting or retrieving data from jTable we have to define a specific model called DefaultTableModel (javax.swing.table.DefaultTableModel). This model contains rows & columns just like jTable but does not exist on the view or GUI side, because model is just a template that holds data.
In DefaultTableModel we can set as many columns as we want and we can set any column as a Date type or Boolean type or any other data type.