LabVIEW VI’s contains of two components: front panel and block diagram, which are close related with each other.

The Front Panel is a visual panel (interface) and represents the control part of the virtual instrument. Usually this window represents the user interface of the application. Here the user can interact with the program when this is working.

The front panel contains various graphic elements (buttons, sliders, switches, graphs, etc.) and serves as the interactive interface for adjusting and observing the phenomenon. In this way users can control the program and see the data updated in real time.

All these elements are considered like control and indication instruments and have a corresponding terminal in the block diagram.

The Block Diagram represent the program of the application which consists of a set of icons and links between used icons, all made in the form of a scheme. It contains the appropriate terminals for control and indication instruments on the front panel, but also constants, functions, structures and connections from one object to another.

So, front panel and block diagram consists of a collection of graphical objects each of them representing elements of LabVIEW programming.