In component-based programming (

Visual Basic Visual Basic is a name for a family of programming languages from Microsoft. It may refer to: * Visual Basic .NET (now simply referred to as "Visual Basic"), the current version of Visual Basic launched in 2002 which runs on .NET * Visual Basic (cl ...

, .NET

WinForms Windows Forms (WinForms) is a free and open-source graphical user interface, graphical (GUI) Library (computing), class library included as a part of Microsoft .NET Core, .NET, .NET Framework or Mono Framework, providing a platform to write client ...

Gambas Gambas is the name of an object-oriented dialect of the BASIC programming language, as well as the integrated development environment that accompanies it. Designed to run on Linux and other Unix-like computer operating systems, its name is a re ...

Delphi Delphi (; ), in legend previously called Pytho (Πυθώ), in ancient times was a sacred precinct that served as the seat of Pythia, the major oracle who was consulted about important decisions throughout the ancient classical world. The oracle ...

, Lazarus etc.), a form is a representation of a

GUI The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

window. A form contains components and controls typically including "OK" and "Cancel" buttons, these objects provide a high-level abstraction of standard or custom widgets which are typically much easier to manipulate than the GUI's underlying API. At design time, visual controls (buttons, text boxes, and the like) and non-visual components (timers,

database connection A database connection is a facility in computer science that allows client software to talk to database server software, whether on the same machine or not. A connection is required to send commands and receive answers, usually in the form of a r ...

s, layout aids and so on) are placed on the form. These controls and components are positioned and sized interactively, and their properties and

event handler In programming and software design, an event is an action or occurrence recognized by software, often originating asynchronously from the external environment, that may be handled by the software. Computer events can be generated or triggered ...

s are set with a special editor typically laid out as a grid. At runtime, automatically generated code creates instances of these controls and components, and sets their properties. Historically, forms were often implemented as screens on a

block-oriented terminal A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. The teletype was an example of an early-day hard-copy terminal and ...

connected to a mainframe computer.

HTML forms A webform, web form or HTML form on a web page allows a user to enter data that is sent to a Server (computing), server for processing. Forms can resemble form (document), paper or database forms because web users fill out the forms using checkboxe ...

are conceptually very similar.

See also