Metadata

What is "Metadata" in the Computer?

Metadata is data about other data. A common example would be the "properties" of a file. The data of a file are the bytes contained inside of it: a text file whose content is only the word file in ASCII encoding would have 4 bytes of size, because the word has 4 letters and in ASCII each letter occupies exactly 1 byte. However, if we were to save this file, we would need to give it a filename, e.g. example.txt. This text, example.txt, has 11 characters (letters and punctuation), which in ASCII would be 11 bytes. Therefore, if it was only this, the data of the file would be 4 bytes, while the metadata (the name) would be 11 bytes. Naturally, both data and metadata need to be saved in the hard disk to really save the file, so the total size of this file would be 15 bytes.