A system user is a person who interacts with a system, typically through an interface, to extract some functional benefit. User-centered design, often associated with human–computer interaction, considers a wide range of generic systems. System user also defines the behaviour of the system operations and how the audience(end-user) would interact with the system using pre-designed triggers such as buttons/mouse/keyboard. In order for the system to work on a larger scale using various databases system would have to create an interface that would be suitable for specific level of knowledge that the end user acquires.
Users authorized to change the way the system behaves are often called operators. Users who rely on a system, but do not operate it, are sometimes called the audience or end user.
Different types of system structure use different triggers. Some triggers require user to do certain action (e.g. type phone number for the system to call that person), others get triggered by certain activities related to the user (e.g. person calling user`s phone), however in both types of the system the output could be similar (e.g. phone rings).
In most of the systems there are two different types of users, Single-User (e.g. car driver) type of system is only targeted at one user and others cannot interact with the system at the same time with the main user, Multi-User (e.g. university portal) is the type of system where more than one user can interact with interface simultaneously.
Depending on the type and purpose of the system operators can either be triggered by the system user himself or by the actions related to the purpose of the system and user. Input or trigger is usually related to the user actions or inserted by the user himself in order to activate the system. Modern triggers include keyboard/mouse/microphone/buttons.
System could be of two types, hardware or software, system connects all the variables and input that are triggered and sent by an operator to produce certain output that the system designer has made the system to do. Output could have many different types, in software systems the output is usually sound/picture and sometimes certain motion outputs as vibration or movement, in hardware system the output can be very different and related to the system purpose (e.g. electrical output) that activates different triggers of the system to do its purpose. Many of the modern systems connect both the hardware and software system in order to manage different purposes (e.g. smartphone).