In this dialog you may enter a default password, which will apply to the add, extract, test and view operations.
If "Show password" option is disabled and password is requested for archiving operation, you will be asked to type the password twice to ensure correctness.
If you set "Encrypt file names" option, WinRAR will encrypt not only file data, but all other sensitive archive areas like file names, sizes, attributes, comments and other blocks, so it provides a higher security level. Without a password it is impossible to view even the list of files in archive encrypted with this option. This option makes sense only when compressing data to RAR archive, it is ignored when the default password is used to decompress data or to compress to ZIP.
If you enabled "Use for all archives" option and entered the empty string as a password, extract and test commands will skip all encrypted archives. All attempts to open encrypted files and archives will also be blocked until this option is turned off. This mode can be convenient if you are going to unpack a group of archives in unattended mode and want to avoid password prompts. "Use for all archives" is not available for non-empty passwords, because non-empty default passwords are applied to all archives automatically, without any additional options.
If you already saved some passwords, you can access them either using the drop down list associated with "Enter password" field or utilizing the autocomplete feature. Press "Organize passwords..." button to open "Organize passwords" dialog, where you can save frequently used passwords.