Two people talking

Interaction is a kind of action that occur as two or more objects have an effect upon one another. The idea of a two-way effect is essential in the concept of interaction, as opposed to a one-way causal effect. A closely related term is interconnectivity, which deals with the interactions of interactions within systems: combinations of many simple interactions can lead to surprising emergent phenomena. Interaction has different tailored meanings in various sciences.[citation needed] Changes can also involve interaction.

Casual examples of interaction outside science include:[citation needed]

  • Communication of any sort, for example two or more people talking to each other, or communication among groups, organizations, nations or states: trade, migration, foreign relations, transportation.
  • The feedback during the operation of a machine such as a computer or tool, for example the interaction between a driver and the position of his or her car on the road: by steering the driver influences this position, by observation this information returns to the driver.


In physics, a fundamental interaction (depending on the nature of the interaction, it might also be called a fundamental force) is a process by which elementary particles interact with each other. An interaction is often described as a physical field, and is mediated by the exchange of gauge bosons between particles. For example, the interaction of charged particles takes place through the mediation of electromagnetic fields, whereas beta decay occurs by means of the weak interaction. An interaction is fundamental when it cannot be described in terms of other interactions. There are four known fundamental interactions in nature: The electromagnetic, strong, weak and gravitational interactions. The weak and electromagnetic interactions are unified in electroweak theory, which is unified with the strong force in the standard model.

Other Languages
العربية: تآثر
беларуская: Узаемадзеянне
български: Взаимодействие
Deutsch: Interaktion
Esperanto: Interago
فارسی: برهم‌کنش
français: Interaction
galego: Interacción
한국어: 상호작용
Bahasa Indonesia: Interaksi
íslenska: Víxlverkun
italiano: Interazione
Basa Jawa: Interaksi
қазақша: Өзара қимыл
Кыргызча: Өз ара аракет
latgaļu: Mejveice
Nederlands: Interactie
日本語: 相互作用
português: Interação
српски / srpski: Интеракција
svenska: Interaktion
українська: Взаємодія
اردو: تعامل