An approach to understanding reality in hybrid manner as a set of related human-nonhuman actors. Wikipedia article here.
Actor–network theory (ANT) is an approach to social theory and research, originating in the field of science studies, which treats objects as part of social networks. The fundamental aim of ANT is to explore how networks are built or assembled and maintained to achieve a specific objective. Although it is best known for its controversial insistence on the capacity of nonhumans to act or participate in systems or networks or both, ANT is also associated with forceful critiques of conventional and critical sociology. Developed by science and technology studies (STS) scholars Michel Callon and Bruno Latour, the sociologist John Law, and others, it can more technically be described as a "material-semiotic" method. This means that it maps relations that are simultaneously material (between things) and semiotic (between concepts). It assumes that many relations are both material and semiotic.
Broadly speaking, ANT is a constructivist approach in that it avoids essentialist explanations of events or innovations (i. e. ANT explains a successful theory by understanding the combinations and interactions of elements that make it successful, rather than saying it is “true” and the others are “false”). However, it is distinguished from many other STS and sociological network theories for its distinct material-semiotic approach.