ZIP files are compressed archives that bundle multiple files and folders into one smaller, easier-to-transfer package. Their core function is efficient storage and transfer, not inherently guaranteeing safety. Opening a ZIP file itself is generally safe, but the risk lies entirely with the contents inside. Malicious actors often hide malware within compressed files, exploiting the fact the harmful payload isn't visible or executed until extracted. Safety fundamentally depends on trusting the source of the ZIP file and scanning its contents.

Users frequently encounter ZIP files as email attachments containing documents, software installers downloaded from websites, or backups shared via cloud storage. For instance, a colleague might send project assets as a ZIP email attachment, or a legitimate software vendor might distribute their program as a compressed download to reduce transfer size. Tools like built-in OS utilities (e.g., Windows File Explorer, macOS Archive Utility), WinZip, and 7-Zip are common for creating and opening these archives.

The main advantage of ZIP files is their convenience for sharing groups of files efficiently. However, a significant limitation is their potential as a malware delivery vehicle, as compressed contents bypass some email security scans and hide harmful executables. This risk necessitates caution: only open ZIP files from trusted sources, keep anti-virus software updated to scan upon extraction, and be wary of unexpected attachments. Security tools increasingly include decompression scanning, and enhanced digital signatures offer potential future safety improvements, but vigilance remains essential.