Worldwide, the population ageing is a reality. The concept of Active Ageing, adopted by the World Health Organization, aims to guarantee quality ageing and appears as a strategy to solve this demographic challenge. The technological solutions might have a key role in the promotion of human functioning and in the mitigation of disabilities, particularly those resulting from the natural ageing process. This perspective is evident in the development of Ambient Assisted Living (AAL) solutions. In this context, it is relevant to know about the recent developments in AAL and discuss future trends and challenges in this area. One of the objectives of this book is to do a systematic literature review on AAL, not only considering the technology used, but also the health condition that is intended to improve. For this purpose, we consider the human functioning, in particular the conceptual model of International Classification of Functioning, Disability and Health (ICF). Considering that the ICF conceptual framework is accepted within the healthcare domain, the use of its concepts and terminologies to promote multidisciplinary approaches for AAL solutions development processes can help to overcome difficulties of communication between users, careers and technological developers. AAL solutions must consider in their development the needs of the person that will use AAL solutions. The development must be user-centred and usability questions cannot be forgotten. In addition, the acceptance of the AAL solutions is closely related to the quality of the systems, so it is necessary to appropriately assess these solutions.