The objects handled by a visual language can thus be considered as object icons or icons with a logical part and a physical part representing an object. Similarly, the programming language constructs in a visual language can be considered as process icons or icons with a logical part and a physical part representing a computation process.
The distinction between an object icon and a process icon depends both upon context and interpretation. For example, the road sign of a diagonal line inside a circle can be interpreted as a stop-sign by a computer vision system. It is an object icon under this latter interpretation. On the other hand, it could also be interpreted as a halt command by a mobile robot. It is a process icon (or action icon) under this interpretation.