  Agents and agent systems are becoming more and more important in the
development of a variety of fields such as ubiquitous computing, ambient
intelligence, autonomous computing, intelligent systems and intelligent
robotics. The need for improvement of our basic knowledge on agents is very
essential. We take a systematic approach and present extended classification of
artificial agents which can be useful for understanding of what artificial
agents are and what they can be in the future. The aim of this classification
is to give us insights in what kind of agents can be created and what type of
problems demand a specific kind of agents for their solution.
