Archives.
WHAT COMPRESSION DOES
Reduces file size, and combines several files into one.
WHEN TO USE IT
Sending several files at once Reducing transfer size Archiving completed work
WHAT COMPRESSES WELL
Documents and text.
WHAT DOES NOT
Photographs, video and audio, which are already compressed.
WHAT THAT MEANS
Compressing a folder of photographs saves almost nothing.
HOW TO CREATE ONE
Most systems provide this without additional software.
HOW TO OPEN ONE
Extract it, rather than working inside it.
WHY
Programs behave unpredictably with files inside an archive.
WHAT TO BE CAREFUL WITH
Archives from unknown sources Archives that expand to far more than expected Password-protected archives sent unexpectedly
THAT LAST ONE
A common way of delivering malicious files past scanning.
WHAT TO CHECK BEFORE EXTRACTING
Where it will extract to.
WHAT TO DO AFTER
Delete the archive, if the contents are what you needed.
