Home security is about protecting your body, your assets, and your information at your place of residence.
For your body, consider the spectrum of temporary injuries (ex. small cut) and permanent damage (ex. serious concussion).
For your assets, consider the replacement expense (ex. purchasing a new car) and the opportunity cost (ex. unable to fly without passport).
For your information, consider the risk of identity fraud (ex. social security number), unauthorized charges (ex. credit card), blackmail (ex. sensitive emails), and criminal account access (ex. online banking).
Risk factors include artificial causes (ex. random theft, police confiscation) and natural causes (ex. fire, flood, earthquake).
For asset protection, home security includes obfuscation (ex. valuables are hidden in a cereal box), locking (ex. opening the main door requires a key), and anchoring (ex. heavy safe cannot be carried easily; large cabinet cannot fit through the doorway without disassembly).
The average family will do well by locking all entry doors consistently, installing an alarm system, and storing valuables and sensitive items in a large, strong, lockable container that cannot be moved out of its room without disassembly and cannot be disassembled from its exterior.
For superior protection, consider a real-time surveillance service (notifies you and calls the police when alarms are tripped) and storing valuables in a fire-proof and water-proof safe within the larger immovable, lockable container.