** This question is for Cyanogen OS and not Cyanogen Mod.
On the Cyanogen OS download page, for my device (YU Yuphoria), I see 3 different downloads for my device, i.e.
cm-12.1-YOG4PAS47N-lettuce-signed-fastboot-5d674b9b61.zip
cm-12.1-YOG4PAS47N-lettuce-signed-806afa8c62.zip
cm-12.1-YOG4PAS47N-lettuce-boot-debuggable-c915697c50.img
It is clear that the first one is the firmware which is to be flashed over fastboot, but I'm skeptical about the second & the third one..
What do the 2nd & the 3rd link provide?