The first type of privacy is "privacy of space". This is the ability to control who does and does not enter a particular physical space, probably because you're in the space and you don't want certain others in that space. "Enter the space" in that definition includes any method of being able to perceive the space – so, for example, if somebody stands outside the door with their ear pressed to it, they're violating your privacy. If somebody installs a camera in your room without your consent, they're violating your privacy.
This form of privacy is not metaphorical. It does not apply to anything other than physical space. It literally means, "I do or do not want you to be perceiving this physical location, and I have the choice and ability to control that."
The most common reason that we want this form of privacy is that we want to protect somebody or something from harm, most commonly ourselves. This harm can be minor (we don't want to be annoyed by people walking through...