Quick backstory ;

I game on an Android device (Xperia play) and only recently found out how to use Emulators and ISO/Roms.When i tried extracting a few games from here (MGS and FFVII) they had a CUE file,which is MUCHHHHH shorter than the .BIN file.Using a portable device means i have a SD card,thus limited memory,i need an answer.

Are Cue the same as bin files?

i need memory,and since these are MULTI-DISK games,i'd like cheaper on the memory bytes for the complete experience.

Thnx!