TDM plugins run on dedicated DSP chips. Native plugins run on the host computer. Pro Tools and dedicated DSP used to kinda go hand in hand once upon a time when computers weren't every remotely as powerful as they are now. But modern CPUs can do billions and billions of operations on billions of audio samples every second (especially when they take advantage of SIMD and simultaneous vector processing and all that shit)...and still have 3 cores left to check your email, play youtube videos and run Call Of Duty all at the same time. There's just no need for outboard DSP help anymore, and no other DAW really even supports anything other than native plugins. Pro Tools' support for TDM is mostly about them being backwards compatible for people who bought expensive TDM plugs back in the days when they were...helpful. Avid recently said they're retiring TDM completely (finally).
