On Windows, open File Explorer
Click the View menu
Select Show
Turn on Hidden items
On macOS, open Finder
Press Command + Shift + .
Press the same keys again to hide them
On Linux, open your file manager
Enable Show Hidden Files
Press Ctrl + H in many file managers
In terminal on macOS or Linux, use ls -a to list hidden files
In terminal on Windows PowerShell, use Get-ChildItem -Force to list hidden files