LabVIEW stands for Laboratory Virtual Instrumentation Engineering Workbench and is a graphical programming system by National Instruments. The programming language is called G but often referred to as just LabVIEW.
LabVIEW is a graphical development environment offered as proprietary software by National Instruments and complementing their industrial controllers and data acquisition systems used in research labs and elsewhere.
The programming language itself is called G but usually referred to as just LabVIEW. The programming language is a parallel, dataflow, graphical, type-safe language. Dataflow provides automatic memory allocation/deallocation without the overhead of garbage collection. The language includes hooks to call into native C, .NET, COM, etc.
A LabView application is represented by a so-called "virtual instrument" or VI. A VI is divided into two parts: the front panel and the block diagram. The front panel acts as the GUI and defines the user interface where all the visual elements ("controls") are drawn and placed. Front panel controls include buttons, switches, knobs, and so on. Output elements like graphs, thermometers, and text boxes are also placed on the front panel.
The block diagram contains the execution code. LabVIEW code follows a dataflow-based execution paradigm. Functions are represented as individual blocks on the block diagram, with each function having zero or more inputs and one or more outputs. The dataflow programming paradigm dictates that a block (function) cannot execute until it has received data on all of its inputs, and a block outputs data on all of its outputs simultaneously once it has executed. Each block is, from the perspective of the block diagram in which it resides, atomic. Wiring determine execution order between blocks, and sections of a block diagram that share no connections can run completely in parallel.
To include LabVIEW code in your question, consider using a VI Snippet so that others can view, run and edit your code.
You can read more on the LabVIEW wiki or on the official National Instruments website.