Wide chassis vs. Slim chassis.
Manufacturers are pushing one or the other, I believe they can work the same in different conditions.
Wide chassis have more flex, anything that unsettles the car is filtered through both suspension and chassis flex. They also have the components spread a little more than a slim chassis which means when a wheel goes through a bump the suspension has more "inertia" and the bump is absorbed better than similar shock package on a slim chassis.

The slim chassis has less flex inherently and requires a better shock package setup to absorb the bumps as good as a wide chassis. Performance differences between the two types is not night and day, I see the wide chassis as a tuning option because tracks around me aren't that bumpy and jumps are "small".