SECAM means Séquentiel couleur à mémoire and is french for "Sequential Color with Memory".
It is a way of encoding colour information in the analog TV signal like PAL or NTSC.
The colour information itself is the same as in the PAL norm.
The resolution and refresh-rate of SECAM analog signals are the same as PAL analog signals: 576i meaning 576 vertical lines with 50 interlaced half-frames per second.
So in digital broadcasting (DVB) or media (DVD) there is no difference in the digital data between PAL and SECAM!
Nevertheless we speak e.g. of "PAL-DVDs" to differentiate them from "NTSC-DVDs".
The different DVD labels relate mostly to the different refresh rate (50Hz PAL vs. 59.94Hz NTSC) usually accompanied by a different vertical resolution (576 lines PAL vs. 480 lines NTSC)