What is the default behavior of tar if no options are specified?

The default behavior of the tar command, when no options are specified, is to extract files from an archive. This is significant because it means that if a user simply types tar without options or arguments, tar will assume that the intention is to restore the contents of an existing archive back to the filesystem.

The design choice to default to extraction reflects a common use case where users want to retrieve files from archives, as opposed to creating new ones or listing contents, which may require additional commands. It is essential to note that for safer use, it is good practice to specify the intended action explicitly, such as using the -c option for creating a new archive or the -t option for listing contents, to avoid unintentional data extraction.