What makes a phar a phar and not a tar or a zip?
Phar file stub
What makes a phar a phar and not a tar or a zip?
PHP Manual

## Ingredients of all Phar archives, independent of file format

All Phar archives contain three to four sections:

1. a stub

2. a manifest describing the contents

3. the file contents

4. [optional] a signature for verifying Phar integrity (phar file format only)

What makes a phar a phar and not a tar or a zip?
Phar file stub
What makes a phar a phar and not a tar or a zip?
PHP Manual