It typically covers your ethnicity, sex, military background (if any), disability (if any) or other factors that provides the employer with information that may simply be passed onto the federal government or actually used to balance out the staff. I'm not an HR person so I really don't know how the information gets used.
A job application can ask a number of demographic information especially if it relates to security. An application can ask how long the applicant has lived at the address. This information is needed for background checks and to determine stability.
Yes, I have voluntarily disclosed information on a job application before.
religion
religion
Information about how to send a application for a job at the department of defense can be found at your local job centre. They provide you all requirements and information you need.
A Target job application applies you for a job at Target. It basically gets you signed up for a career at the Target store. On the application, you must give your basic information, times of when you can work, etc.
On a job application, when you are asked for prior Demographic information, it probably means previous names (maiden name), change of address, etc - look to see if it has space for a name or something; that should clue you in.
any other information you wish to provide in job application like junior research fellow
If you omit something from a job application you should let the employer know. You can get fired from a job for omitting information or lying on a job application. It may depend on the type of information that you omitted on what type of action the employer can and will take.
names of friends
Yes, an employer can legally terminate an employee for providing false information on their job application. This is considered a breach of trust and can be grounds for dismissal.
Considering that the purpose of a job application is to get an interview, you could write something like: I will provide more information during an interview. Or, Please call me for more information.