The Web of Trust (WOT) is a cryptographic concept that allows users to authenticate the connection between a public key and its owner. This concept is essential to establishing trust and verifying identities within a network with public-key cryptography.
WOT enables users to sign each other's public keys to indicate that they have verified the association between the key and its owner. Over time, a web of trust relationships forms, creating a network of authenticated public keys. If someone trusts the key of another person and that person trusts a third person's key, there is an implied level of trust extended along the chain.