Why is @AfterSuite getting executed for every other annotation present without any body?

I created all the TestNG annotations in a file before providing them any method, and ran just to see the order. The method annotated with @AfterSuite is being run for every annotation present in the file.

public class ChronologicalOrder {
    
    @BeforeSuite
    
    @BeforeTest     
    
    @BeforeClass
    
    @BeforeMethod
    
    @Test   
    
    @AfterMethod
    
    @AfterClass
    
    @AfterTest
    
    @AfterSuite
    public void afterSuite() {
        System.out.println("After suite");
    }
}

Here is the output :

After suite
After suite
After suite
After suite
After suite
After suite
After suite
After suite
PASSED: testNg.ChronologicalOrder.afterSuite

===============================================
    Default test
    Tests run: 1, Failures: 0, Skips: 0
===============================================

After suite

===============================================
Default suite
Total tests run: 1, Passes: 1, Failures: 0, Skips: 0
===============================================

That is because you have the same method but annotated with different TestNG annotations. So TestNG ends up executing the same method but for different annotations.

Here's an annotated explanation of what each of those outputs means

After suite <-- BeforeSuite
After suite <-- BeforeTest
After suite <-- BeforeClass
After suite <-- BeforeMethod
After suite <-- Test
After suite <-- AfterMethod
After suite <-- AfterClass
After suite <-- AfterTest
After suite <-- AfterSuite

If you run this modified sample it should be more clear

import org.testng.ITestNGMethod;
import org.testng.Reporter;
import org.testng.annotations.*;

public class ChronologicalOrder {
    @BeforeSuite
    @BeforeTest
    @BeforeClass
    @BeforeMethod
    @Test
    @AfterMethod
    @AfterClass
    @AfterTest
    @AfterSuite
    public void afterSuite() {
        ITestNGMethod method = Reporter.getCurrentTestResult().getMethod();
        if (method.isBeforeSuiteConfiguration()) {
            System.err.println("Before <suite> mode");
        }
        if (method.isBeforeTestConfiguration()) {
            System.err.println("Before <test> mode");
        }
        if (method.isBeforeClassConfiguration()) {
            System.err.println("Before class mode");
        }
        if (method.isAfterClassConfiguration()) {
            System.err.println("After class mode");
        }
        if (method.isBeforeMethodConfiguration()) {
            System.err.println("Before method mode");
        }
        if (method.isTest()) {
            System.err.println("Test case mode");
        }
        if (method.isAfterMethodConfiguration()) {
            System.err.println("After method mode");
        }
        if (method.isAfterTestConfiguration()) {
            System.err.println("After <test> mode");
        }
        if (method.isAfterSuiteConfiguration()) {
            System.err.println("After <suite> mode");
        }
    }
}

The output would now look like:

Before <suite> mode
Before <test> mode
Before class mode
Before method mode
Test case mode
After method mode
After class mode
After <test> mode
After <suite> mode

===============================================
Default Suite
Total tests run: 1, Passes: 1, Failures: 0, Skips: 0
===============================================