What is the difference between safe and vault, where both the words refer to a place where to put things you want to keep safe?
As additional question, why does vault seem more frequently used in computer jargon? For example, the Mac OS X has a File vault, and vault is the word used from anti-virus programs to refer to a place where infected files are kept.
A safe connotes something smaller than a vault, and may be movable, while a vault is generally built in-place and would be torn down rather than moved.
The computer jargon use of vault may be due to its connotation of greater security. It is also attractive because it is less common, and is only a noun (in this sense) and thus quicker to interpret, whereas safe can be noun, verb, or adjective (and heavily used in the latter sense in the computer security context).
A safe is usually smaller than a vault. Safes are often portable, or at least movable, while vaults often are entire rooms.
A safe has one layer of steel surrounding the interior shell. The Department of Justice requires a minimum of 12 gauge steel to call it a safe. Otherwise, it's a cabinet. A quality safe will have c-rated fire board underneath the steel to protect against fire. A vault has a layer of steel on the outside, fire board and then an additional layer of steel on the inside. A good quality safe with 7 gauge (3/16") steel that's 60x40x28 will run about $3000 before adding any options or upgrades. That same safe made into a vault by adding that second layer will cost about $3800. If you were to add a layer of 304 stainless steel, it would be impervious to torch cutting and would cost about $5400.
Safe = one layer of steel
Vault = 2 or more layers of steel
