psx on ps2??

[zuzu]

i have a ps2 and was under the impression that i could play copied psx games on the ps2 console. only some of the games work.some need the boot disk, others dont and some just wont work at all. is this normal??
also if i dont have a dvdr..can i read the dvd with a dvd rom (not sure of the term) , make an image and burn it with a cd burner?

thanks in advance...i appreciate you taking the time

zuzu