Yes, There Is a Difference Between 3D Touch and Force Touch | WIRED

3D Touch > Force Touch; also see How Apple Built 3D Touch (BloombergBusiness)

"According to Apple patents, there is another level of sensitivity of Force Touch that will be used in the new iPhones. Basically, these two technologies do the same things, but what you’ll see in the newest iPhones is an additional level of sensitivity. Simply put, Force Touch has less capability to measure your touches and presses and doesn’t react as quickly to your input, whereas the new 3D Touch is highly sensitive and reacts immediately, while also allowing different “levels” of actions based on how firmly you press."

Yes, There Is a Difference Between 3D Touch and Force Touch | WIRED