A Sybil Attack occurs when a single entity creates multiple fake identities to gain a disproportionate influence over a network. This manipulation can disrupt the overall functioning of decentralized systems.In a blockchain environment, participants often rely on consensus mechanisms to validate transactions. If an attacker generates numerous false identities, they can overwhelm legitimate users and skew decision-making processes. This might lead to issues like double-spending, where the same digital assets are used more than once.To guard against Sybil Attacks, networks implement measures such as requiring proof of work or proof of stake, which make it costly or difficult to create multiple identities. These techniques help ensure that a single source cannot easily control the network, maintaining its integrity and security.