Recognition or more specifically Pattern or Object recognition is a typical characteristic of human beings and other living organisms. The term pattern or object means something that is set as an idea to be imitated. For example, in our childhood a shape ‘A’ is shown to us and we are asked to imitate that. So the shape is the ideal one. On the other hand, if what we produce or draw obeying that instruction is close to that shape, our teacher identifies that as ’A’. this identification is called recognition and the shapes we draw (that is object we made) may be termed as patterns. Thus, the pattern recognition means identification of the real object. Recognition should, therefore, be preceded by the development of the concept of the ideal or model or prototype. This process is called Learning. In most real life problems no ideal example is available. In that case, the concept of ideal is abstracted from many near perfect examples. Under this notion learning is of two types : supervised learning if appropriate label is attached to each of these examples ; and unsupervised learning if no labeling is available
