JTable is a component in the Java Swing library that displays data in a tabular format. It provides a way to display and manipulate tabular data with many built-in features such as sorting, filtering, and editing. JTable can be customized by modifying the default rendering and editing mechanisms provided by the Swing library.

Here is a simple example of how to create and display a JTable in Java:

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;

public class JTableExample {

    public static void main(String[] args) {
        // Create data for the table
        Object[][] data = {
                {"John", "Doe", 25},
                {"Jane", "Doe", 27},
                {"Bob", "Smith", 30},
                {"Tom", "Jones", 32},
                {"Sue", "Johnson", 24}
        };
        
        // Create column headers
        String[] columnNames = {"First Name", "Last Name", "Age"};
        
        // Create JTable with data and column headers
        JTable table = new JTable(data, columnNames);
        
        // Create a scroll pane for the table
        JScrollPane scrollPane = new JScrollPane(table);
        
        // Create a JFrame and add the scroll pane to it
        JFrame frame = new JFrame("JTable Example");
        frame.add(scrollPane);
        
        // Set the size and visibility of the JFrame
        frame.setSize(400, 200);
        frame.setVisible(true);
    }
}

This creates a simple JTable with five rows and three columns, and displays it in a JFrame with a scroll pane. The resulting table can be sorted by clicking on the column headers, and the cells can be edited by double-clicking on them.