Visual programming

A visual programming language is designed to be interactive. Using wires and pictures to represent equalities and functions instead of complicated text expressions 
    Block-diagram based visual programming ,  Block-diagram based visual language including matrix easy5 simulink vissim and lab view

    All block diagram languages consists of two fundamental objects: 

• Signal wires
• blocks 

1. Signal wire: A single wire transmits a signal or a value from its point of origination(block) to its point of termination(another block). The direction in which the signal flows is defined by an arrow head on the signal wire. Once the flow direction has been defined for given signal wire, signals may only flow in the forward direction. 
2. Block: A block is a processing element that operates on input signal and parameters or constant to produce output signals. 

There is a 3 block basics that all block diagram languages possess 

• summing junction
• gain
• integrator blocks