What is the meaning of " Lockdown "

This article is about the emergency measure. For the mass quarantine measure, see Stay-at-home order. For the practice of isolating prisoners, see Solitary confinement. For the activist tactic of attaching oneself to an object, see Lock-on (protest tactic).

A lockdown is an emergency protocol that usually prevents people or information from leaving an area. The protocol can usually only be initiated by someone in a position of authority. Lockdowns can also be used to protect people inside a facility or, for example, a computing system, from a threat or other external event. Of buildings, a drill lockdown usually means that doors leading outside are locked such that no person may enter or exit. A full lockdown usually means that people must stay where they are and may not enter or exit a building or rooms within said building. If people are in a hallway, they should go to the nearest safe, enclosed room.

A preventive lockdown is a preemptive action plan implemented to address an unusual scenario or a weakness in system to preempt any danger to ensure the safety and security of people, organisation and system. The focus for preventive actions is to avoid dangers and risks arising from the nonconformances to the normal circumstances, but also commonly includes improvements in efficiency.

Preventive lockdowns are preemptive lockdowns to mitigate risk. Most organisations plan for the emergency lockdowns but fail to plan for other situations which might quickly degrade to dangerous levels. These protocols must be based on the type of threat, and should be kept simple and short for quick learning and implementation, and flexible enough to handle several scenarios. This allows administrators more options to choose from which are easier to use in various scenarios. 

For example, in case of a loud scene by a parent or an unarmed petty thief being chased by the police through the school playground, this flexible procedure allows school administrators the flexibility to implement a more limited lockdown while teaching in school continues, this eliminating need for complete emergency lockdown, disruption and delays in resumption of teaching, etc. The consequences of not having procedures to implement such lockdowns is that the situation might quickly escalate where there could be loss of human lives.

Emergency lockdowns are implemented when there is imminent threat to the lives or risk of injury to humans, for example, a school's emergency lockdown procedures must be kept short and simple to make them easier to use under real life crisis conditions. Simple procedures can be easily taught with periodic lockdown drills instead of lengthy training.

most organizations to function normally, or limit movements or activities such that only organizations supplying basic needs and services can function normally.