OBD request trouble code mode 3 and mode 7

I’m trying to get my own app on phone to read Trouble code in car…
I see that i have 3 mode to do this… first is to use the mode 01 with command 01 (but this command is generic) or the mode 03 and 07.

From documentation of the ELM Eletronics
they use mode 0101 and after mode 03 for getting trouble code.

But i read that the mode 07 give trouble code too, but in my case i disconnect a cable of my car and with command 03 i receive the error P0105 but with command 07 i receive two trouble code… P0105 and P0110.

So which is the best between mode 03 and mode 07…they are different?