In cybersecurity, a Man-in-the-Middle (MitM) attack happens when a threat actor
manages to intercept and forward the traffic between two entities without either of them noticing. In addition, some MitM attacks alter the communication between parties, again without them realizing.
To pull this off, the attacker should not only be convincing in their impersonation but also be able to follow and influence the conversation between two or more parties.
A MitM attack can be done between browser and Internet, for example, or between a Wi-Fi hotspot and an Internet user.