ABSTRACT
In this chapter, the definition, scope, and a brief overview of astrobiology are given. Classification of astrobiology as a field of study, its specific goals, its multidisciplinary and interdisciplinary nature, and selected key developments are described. Astrobiology includes numerous research themes, which are expanding as the field evolves. Thus, it is not possible to cover all the developments in a single chapter, even briefly. Instead, an overview of selected astrobiology developments is presented, which is only a sampler of what is offered in this handbook.
