Explain the difference between `fs.readFile()` and `fs.createReadStream()` for reading files in Node.js.
fs.readFile()reads the entire file into memory and then invokes the callback with the file's contents. It's suitable for small files but can be memory-intensive for large files.fs.createReadStream()reads the file in smaller chunks (buffers) and allows for streaming the file's contents. It's more memory-efficient and suitable for handling large files.