To help prevent unauthorized users from seeing your document, you can require a Password to open the file.
When you set a Password to open a document, encryption is used to protect the contents of the file. You can even choose the type of encryption used on the document. Think of encryption as a type of lock and the password as the key.
In the practice session, you'll see how to choose the type of encryption used on a document. The Quick Reference Card also contains a link to more information about encryption.
You can also choose to let other people read your document (known as a read-only document), but require a Password to modify it.
Requiring a password to modify a file does not encrypt the file contents. This setting stops people without the password from saving their changes in your original document, but it does not stop them from making changes and saving the document in a new file with a different name.
Note You can set both types of passwords on a single document, requiring a password to open it and a password to modify it.