In Node.js, there are two ways to read and execute files: readFile and CreateStream.

• The readFile() process is a fully buffered process that returns the response only when the complete file is pushed into the buffer and is read. This process is called a memory-intensive process, and in the case of large files, the processing can be very slow.
• On the other hand, the createReadStream() is a partially buffered process that treats the entire process as an event series. The entire file is split into chunks and then processed and sent back as a response one by one. After completing this step, they are finally removed from the buffer. Unlike the readFile process, the createReadStream process is effective for the processing of large files.