What are the differences between survival mode and normal game?

From this FAQ:

Q: What is survival mode?

A: Survival mode is a significantly harder version of the same game. Incidents occur much more frequently and are tougher, resources are consumed faster, and dweller death is permanent (no reviving). Another important thing to note is that in a normal vault deathclaws only attack at 61 population and higher, while in a survival vault they attack at 35 population and higher. You check a box off at the top on the vault creation screen, and it warns you twice about the difficulty asking if you're sure. Survival mode vaults will be marked with a radiation symbol with an "S" on it in the vault list.

(emphasis my own, to highlight the differences)