How Is NASA Still in Contact With The Voyagers?

The Voyager spacecraft are more than 20 billion km away from us. Launched in 1977 to explore the solar system's outer planets, Voyager and Voyager 2 continued their journey after completing their primary missions. Today, Voyager 1 is the farthest man-made object from the Earth. At a distance of 21 billion km, even signals take hours to reach there.
But have you ever wondered how NASA is still in contact with these two spacecraft? The answer is the Deep Space Network! But how does it work? The second episode of 'Ever wondered' answers it!