In the book and newspaper printing process, "hard copy" refers to a manuscript or typewritten document that has been edited and proofread and is ready for typesetting or being read on-air in a radio or television broadcast.
Copies of various system and server activity logs are typically stored on the local filesystem, where a remote attacker – having achieved their primary goals – can then alter or delete the contents of the logs in an attempt to "cover their tracks" or otherwise thwart the efforts of system administrators and security experts.
However, if the log entries are simultaneously given to a printer, line-by-line, a local hard-copy record of system activity is created – which cannot be remotely altered or otherwise manipulated.
The usual dot-matrix printer support for continuous stationery also prevents incriminating pages from being surreptitiously removed or altered without evidence of tampering.
Dead-tree edition refers to a printed paper version of a written work, as opposed to digital alternatives such as a web page.