The "Avalanche Effect" refers to a phenomenon in cryptography where a small change in input data results in a significant and unpredictable change in the output. This property is crucial for ensuring that even minor alterations in the original data lead to entirely different encrypted results, enhancing security. This effect is commonly observed in cryptographic hash functions, such as SHA-256 or MD5. By ensuring that similar inputs produce vastly different hashes, the Avalanche Effect helps protect against attacks that exploit predictable patterns in data, making it harder for unauthorized users to decipher or manipulate the information.