Creating a ZIP file is one of those tasks that's built into every operating system but somehow isn't immediately obvious. Here's how to do it on each platform.
On Windows 10/11, select the files you want to compress (Ctrl+click for multiple files, or drag to select). Right-click the selection and choose "Compress to ZIP file" (Windows 11) or "Send to → Compressed (zipped) folder" (Windows 10). A new ZIP file appears in the same directory. Rename it as needed.
On Mac, select the files in Finder, right-click, and choose "Compress." If you selected multiple files, you get "Archive.zip." If you selected one file, you get "filename.zip." Rename as needed.
On Linux, most file managers support right-click → "Compress." From the command line: `zip -r archive.zip folder/` to compress a folder, or `zip archive.zip file1 file2 file3` for specific files.
To create a ZIP from the command line on any platform, the syntax is consistent: `zip output.zip input_files`. Add `-r` to include subdirectories recursively. Add `-9` for maximum compression (slower but smaller). Add `-e` to add password protection.
For large collections of files, ZIP is efficient enough for most purposes. If you need maximum compression, 7-Zip's 7z format or gzip/tar for Unix-style archives will produce smaller files.