1. Adaptation is a supposedly stationary state which implies a minimal strain between the system and its environment.
2. Adaptability is a permanent process, by which the system produces new adapted states whenever necessary.
W. KARGL explains it in the following way: "As ontogenesis must be understood as drift of structural change in organisms and in environment, there are no better or worse adaptation, but numerous possibilities for the organisms' relations with their environment" (1991, p.577).
Adaptation and adaptability are thus quite antinomic. A perfectly adapted system depends on the perfect stability of the environment to which it has adapted. If this adaptation is so absolute that it cannot be modified anymore, the system is in great danger of being destroyed, should its environment start to change. On the contrary, if it has maintained a potential for new adaptations (i.e. adaptability), it is generally able to respond successfully to new changes in its environment.
Adaptability "consumes" redundancy in order to produce successive adaptive states.
→ "Order from noise principle"