• For example in Java, all the common classes like String, System etc which we have used are in a package called java.lang.

  There are many such packages in Java, for example:

  1. java.util - this package contains utility and data structure related classes like Date, ArrayList, HashSet, etc., which we will learn later.
  2. java.io - this package contains classes which help in reading input and writing output to files and streams.
  3. java.net - this package contains networking related classes.

  If we want to use a Date class which is in java.util package in our class, we need to inform Java compiler that we are interested in using the Date class of java.util package

```
import java.util.*;

public class Example1 {
	public static void main(String[] args) {
		Date currentDate = new Date();
		System.out.println(currentDate);
	}
}

```

```
import java.util.Date;

public class Example2 {
	public static void main(String[] args) {
		Date currentDate = new Date();
		System.out.println(currentDate);
	}
}

```

```
public class Example3 {
	public static void main(String[] args) {
		java.util.Date currentDate = new java.util.Date();
		System.out.println(currentDate);
	}
}-
```