Security refers to security work, which has the nature of work and can be a job, a task or a department. Security means defending public order and actively protecting the safety of others. Refers to a post, a profession or an industry.

Security and security are the same thing, but the scope of security work is larger than security, and security is a kind of security personnel. For example, people who check at the entrance of public places (such as gymnasiums and airports) are also called security personnel. Now security guards refer to people who patrol the streets or watch the door.

Their work scope is different: security and security, which have the same meaning, but the scope of security work is larger than security, and security is a kind of security personnel. For example, holding large-scale activities requires security personnel to maintain order and set up security organizations.