Drop down button?

[thekooliest]

I don't really know what to call this, but I would best describe it as a drop down button. I am looking for a code (or someway to do this ) so I can have a button. And when you click that button, more text appears below the button.
If anyone can help, that would be great

 

[thekooliest]

I just looked a little harder on google, and it is not a drop down button. Because a drop down button is like a button that drops down a menu that is attatched. I don't want that

 

[thekooliest]

I got it. Yay google search...and html editing