How can I create these types of gradient images in Photoshop or Illustrator?

I don't understand how they made these swooshes.

[![Gradient](https://i.stack.imgur.com/s0hYZ.png)](https://i.stack.imgur.com/s0hYZ.png)
[![Gradient example I made](https://i.stack.imgur.com/tPeC6.jpg)](https://i.stack.imgur.com/tPeC6.jpg)
Lower picture is what I came up with... but it's not the same.

Your help is much appreciated. 

Greetings,
Pim