See this website
See in the right side:
Images from our Featured Galleries
Items change about every 20 seconds.
The images change every 20 seconds.
If I want to make this in my website How should I do it?
If you go here you can grab the code that will allow you to do it. (Click on Visit). There are all sorts of different codes to make all types of slide shows out there, but I think this is what you're looking for.