Most home safes have at least a few traits in common. They lock. They're typically heavy. They have drill-resistant steel in the walls and doors. They offer some degree of protection against the elements.
What differentiates a gun safe from a regular security cabinet are the overall dimensions and the interior storage features, both of which vary between models based on the types and numbers of guns they're designed to hold. Some varieties include:
Handgun Safes: A handgun safe can be as small (and as portable) as a briefcase, typically designed to hold one gun and useful for those who take a firearm everywhere. Larger handgun safes can hold multiple guns on multiple shelves in a unit about the size of a milk crate. They can be designed as car consoles for vehicle use.
Long-gun Safes: For longer guns like rifles and shotguns, a tall safe is required. An interior height of about 60 inches (150 centimeters) is good; width depends on the number of guns it can properly store [source: Home Safe HQ]. Capacities can range from one to dozens of guns [source: Tractor Supply Co].
Multi-use Gun Safes: Some "gun safes" are designed to hold long guns, handguns, jewelry, documents and anything else that might warrant increased security. They can be large or small, portable or stationary, and configured with various types of compartments (shelves, drawers, hooks) to securely hold a wide range of items.
In these basic terms, choosing a type of gun safe is pretty simple -- have one handgun and don't plan on buying more? Handgun safe. Avid rifle collector? Go with a high-capacity long-gun safe. But selecting specific features and accessories can be more confusing. Combination or digital lock? Inside or outside hinges? Do you need really humidity control? And what's the relationship between security and price?