Here are the differences between all the versions of ChatGPT. Every time you start a new chat you can choose your model. Here I will outline the benefits and shortcomings of all of them so you know how to use them in different situations.
Default GPT - 3.5
This version is optimized to give you the fastest response but it might not be the most accurate.
Legacy GPT 3.5
The newest version GPT-4
As you can see its optimized for reasoning and it takes much more time to generate response.
