Why do we need a magic number in the beginning of the .class file?

Question

I read a few posts here about the magic number 0xCAFEBABE in the beginning of each java .class file and wanted to know why it

Answer 1

The magic number is basically an identifier for a file format. A JPEG for example always starts with FFD8. It is not necessary for Java itself, it simply helps to identify the file-type. You can read more about magic numbers here.