Buffer.alloc is a method in Node.js used to create buffer objects for handling binary data. Unlike the older Buffer constructor, Buffer.alloc initializes the allocated memory to zero, preventing the accidental exposure of sensitive or uninitialized memory. This method is crucial for security, as using uninitialized buffers (such as those created by Buffer.allocUnsafe) can lead to vulnerabilities where attackers may access leftover data from previous operations. Proper use of Buffer.alloc helps developers avoid these risks and ensures that applications handle memory safely. It is recommended to always use Buffer.alloc unless performance is a critical concern and the buffer will be immediately overwritten.