Mutual TLS (mTLS) is a security protocol that ensures both parties in an online communication verify each other’s identities using digital certificates, not just one side. Unlike standard TLS, where only the server proves its identity, mTLS requires both the client and server to authenticate. This two-way verification greatly reduces the risk of unauthorized access and eavesdropping, making it especially valuable for securing sensitive data transfers between systems, such as in banking, healthcare, or enterprise applications.