It is always better to know the properties before we can go and use a system.
This helps us to realize whether we can use it or not for a given application.
The essential and principal property of the adaptive system is its time-
varying, self adjusting property. This can be better understood by
considering the following. Suppose a designer has developed a system
of fixed design that must meet specific criterion. From that we see that
the designer has chosen the system that appears best according to the
performance criterion selected that has been chosen from a priori restricted
class of designs such as linear systems. But in many instances, however, the
complete range of input conditons may not be known exactly or the conditions
may change from time to time. In such circumstances, an adaptive system that
continually seeks the optimum within an allowed class of possibilities would
give a superior performance compared with a system of fixed design.
From the above a second property for the adaptive system is that it must be
non-linear. By this we mean that the principle of superposition doesnot
hold good. Certain forms fo adaptive systems become linear systems when their
adjustments are held constant after adaptation. They may be called linear
adaptive systems. They are useful in one way because they are easier tho design
than other forms of adaptive systems.