Minecraft wiki entry for The_End, associated text: Beds and respawn anchors cause an explosion 25% stronger than TNT and cause fires when one attempts to use them, as beds do in the Nether and respawn anchors in the Overworld. (Villagers, if somehow brought in, can still use beds safely).
Compasses are unable to find the original spawn point, (except for aiming for Lodestone) as spawn points cannot be set within the End.
Clocks are unable to determine the position of the sun and moon, as there is no daylight cycle in the End. Clocks instead spin randomly as they do in the Nether.
Nether portals cannot be activated by the player in the End (although they can be placed through commands or external programs and editors).
Fire burns indefinitely on bedrock, but does not naturally spread onto other blocks of bedrock, as with netherrack.