JUnit is a Java testing framework used for unit testing and ensuring code correctness.

Explanation:

• Provides annotations like @Test, @Before, @After to structure tests.
• Supports assertions (assertEquals, assertTrue) to validate expected outputs.
• Integrated with Maven, Gradle, and CI/CD tools.

Example JUnit Test:

import org.junit.Test;
import static org.junit.Assert.assertEquals;

public class CalculatorTest {
    @Test
    public void testAddition() {
        assertEquals(5, 2 + 3);
    }
}

• This test checks if 2 + 3 correctly returns 5.