Magic number

A "magic number" in computing refers to a specific value used within code or data files that helps identify or validate the data's format or type. Think of it as a unique tag or signature embedded at the beginning of a file, allowing programs to recognize the file format quickly. These numbers are often fixed and predetermined, serving as a simple check to ensure the data is what the program expects. For example, the first few bytes in a PNG image file contain a magic number that identifies it as a PNG.