What is this thing I sometimes use?

I sometimes use a statement(?) that I have today forgotten how to write and now I can’t find it on Google because I don’t know what to look for…
It looks something like the below and is like a shorthand if… else

( width > height ) ? trace( "width is greater" ) : trace("height is  greater");

Any help on what to call it / how to write it would be appreciated.