A family of Microsoft word processing software products for creating web, email, and print documents.
In fact, you most probably don't want people to turn the protection off -- that leads to unwanted modifications of a 'personal' nature :-) A Password generally is recommendable.
In order to have portions of a document protected & others not, you need to insert Section Breaks. You can then impose protection on a per section basis... When you go to Tools> Protect Document & select the Forms option the Sections button will be active. Leave the checks in place for the Sections to remain protected. See Word Help on how to Insert, delete, or change a section break.