A scientist, in a broad sense, is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist may refer to an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word. Scientists perform research toward a more comprehensive understanding of nature, including physical, mathematical and social realms. Philosophy can be seen as a distinct activity and which many consider not to be a science. It is aimed towards a more comprehensive understanding of intangible aspects of reality and experience that cannot be physically measured. Scientists are also distinct from engineers, those who design, build and maintain devices for particular situations. When science is done with a goal toward practical utility, it is called applied science. An applied scientist may not be designing something in particular, but rather is conducting research with the aim of developing new technologies and practical methods. When science is done with an inclusion of intangible aspects of reality it is called natural philosophy.