Browse Definitions :

controller (computing)

What is a controller (computing)?

A controller, in a computing context, is a hardware device or a software program that manages or directs the flow of data between two entities. In computing, controllers may be cards, microchips or separate hardware devices for the control of a peripheral device. In general, a controller can be thought of as something or someone that interfaces between two systems and manages communications between them.

Who uses controllers?

Anyone who uses a computing device, such as a laptop or smartphone, employs controllers to connect to devices and applications that are used for business or personal activities. Controllers extend a computer's processing power to resources that help improve a user's productivity.

What is the difference between a controller and a driver?

Think of a controller as a component interfacing with the central processing unit and moving data back and forth between the CPU and the device being controlled, such as a printer or disk drive. Controllers typically have a buffer to store data coming either from the CPU or the device being controlled. By contrast, a device driver is a software program that instructs the controller on how to operate. Figure 1 depicts the difference between a controller and a driver as implemented on a motherboard.

how device controllers work with drivers
Figure 1. Device controllers and drivers

Figure 1 depicts circuit boards that have both device drivers and controllers. The controller links to a device, while the driver links the controller with the computer's operating system (OS).

Examples of controllers in technology applications

Control systems and controllers come in many forms and applications. This table offers examples of controller applications.

Examples of Technology Controllers
Type of Controller Functions Performed
Graphics card Integrated circuit card in a computer or, in some cases, a monitor that provides digital-to-analog conversion, video RAM and a video controller so that data can be sent to a computer's display
Game controller Input device for playing video games
Network interface card (NIC) Computer circuit board or card that is installed in a computer so that it can be connected to a network
Wide area network interface card (WIC) Specialized NIC that enables devices to connect to a wide area network
Flash controller Part of flash memory that communicates with the host device and manages the flash file directory
Application delivery controller (ADC) Data center network device that helps manage client connections to complex web and enterprise applications
Baseboard management controller (BMC) Specialized service processor that monitors the physical state of a computer, network server or other hardware device using sensors and communicating with the system administrator through an independent connection
Session border controller (SBC) Device or application that governs the way calls, also called sessions, are initiated, conducted and terminated in a voice over IP network
Primary domain controller (PDC) Role that can be assigned to a server to manage access to a set of network resources -- e.g., applications, printers -- for a group of users
Backup domain controller (BDC) Role that can be assigned to a server to manage access to a set of backup resources -- storage devices -- for a group of users

The importance of controllers

Controllers and drivers provide important links between the computer and devices and applications being used. While the OS controls computer functions, controllers and their associated drivers extend OS functionality to specialized tools and resources that increase a user's productivity.

Learn about the benefits of application delivery controllers, and see what software-defined network data center controllers do in a network.

This was last updated in February 2023

Continue Reading About controller (computing)

  • local area network (LAN)

    A local area network (LAN) is a group of computers and peripheral devices that are connected together within a distinct ...

  • TCP/IP

    TCP/IP stands for Transmission Control Protocol/Internet Protocol and is a suite of communication protocols used to interconnect ...

  • firewall as a service (FWaaS)

    Firewall as a service (FWaaS), also known as a cloud firewall, is a service that provides cloud-based network traffic analysis ...

  • identity management (ID management)

    Identity management (ID management) is the organizational process for ensuring individuals have the appropriate access to ...

  • single sign-on (SSO)

    Single sign-on (SSO) is a session and user authentication service that permits a user to use one set of login credentials -- for ...

  • fraud detection

    Fraud detection is a set of activities undertaken to prevent money or property from being obtained through false pretenses.

  • IT budget

    IT budget is the amount of money spent on an organization's information technology systems and services. It includes compensation...

  • project scope

    Project scope is the part of project planning that involves determining and documenting a list of specific project goals, ...

  • core competencies

    For any organization, its core competencies refer to the capabilities, knowledge, skills and resources that constitute its '...

  • recruitment management system (RMS)

    A recruitment management system (RMS) is a set of tools designed to manage the employee recruiting and hiring process. It might ...

  • core HR (core human resources)

    Core HR (core human resources) is an umbrella term that refers to the basic tasks and functions of an HR department as it manages...

  • HR service delivery

    HR service delivery is a term used to explain how an organization's human resources department offers services to and interacts ...

Customer Experience
  • martech (marketing technology)

    Martech (marketing technology) refers to the integration of software tools, platforms, and applications designed to streamline ...

  • transactional marketing

    Transactional marketing is a business strategy that focuses on single, point-of-sale transactions.

  • customer profiling

    Customer profiling is the detailed and systematic process of constructing a clear portrait of a company's ideal customer by ...