The pre 12.5 stack uses traditional C++ conditionals together with computer vision for highway driving. 12.5 and after is the a single stack setup (at least that's what Musk claims).
The 12.3.6 (or the 12.4.1 that's being trialed right now) is pretty much the current production state of the art for Tesla street level (not highway) single stack self driving where the steering commands are directly issued by the neural network.
The 12.3.6 (or the 12.4.1 that's being trialed right now) is pretty much the current production state of the art for Tesla street level (not highway) single stack self driving where the steering commands are directly issued by the neural network.