A fire alarm system is number of devices working together to detect and alert people through visual and audio appliances when smoke/fire is present. These alarms may be activated from smoke detectors, and heat detectors. They may also be activated via Manual fire alarm activationdevices such as manual call points or pull stations.
In the fields of physical security and information security, access control is the selective restriction of access to a place or otherresource. The act of accessing may mean consuming, entering, or using. Permission to access a resource is called authorization.
Locks and login credentials are two analogous mechanisms of access control.