The right against unsanctioned invasion of privacy by the government, corporations or individuals is part of many countries' privacy laws, and in some cases, constitutions. Almost all countries have laws which in some way limit privacy; an example of this would be law concerning taxation, which normally require the sharing of information about personal income or earnings. In some countries individual privacy may conflict with freedom of speech laws and some laws may require public disclosure of information which would be considered private in other countries and cultures. Privacy may be voluntarily sacrificed, normally in exchange for perceived benefits and very often with specific dangers and losses, although this is a very strategic view of human relationships. Academics who are economists, evolutionary theorists, and research psychologists describe revealing privacy as a 'voluntary sacrifice', where sweepstakes or competitions are involved. In the business world, a person may give personal details (often for advertising purposes) in order to enter a gamble of winning a prize. Information which is voluntarily shared and is later stolen or misused can lead to identity theft.

The concept of privacy is most often associated with Western culture, English and North American in particular. According to some researchers, the concept of privacy sets Anglo-American culture apart even from other Western European cultures such as French or Italian. The concept is not universal and remained virtually unknown in some cultures until recent times. A word "privacy" is sometimes regarded as untranslatable by linguists. Many languages lack a specific word for "privacy". Such languages either use a complex description to translate the term (such as Russian combine meaning of уединение - solitude, секретность - secrecy, and частная жизнь - private life) or borrow English "privacy" (as Indonesian Privasi or Italian la privacy).

The term "privacy" means many things in different contexts. Different people, cultures, and nations have a wide variety of expectations about how much privacy a person is entitled to or what constitutes an invasion of privacy.

Physical privacy could be defined as preventing "intrusions into one's physical space or solitude" This would include such concerns as:

An example of the legal basis for the right to physical privacy would be the US Fourth Amendment, which guarantees "the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures",. Most countries have laws regarding trespassing and property rights also determine the right of physical privacy.

Physical privacy may be a matter of cultural sensitivity, personal dignity, or shyness. There may also be concerns about safety, if for example one has concerns about being the victim of crime or stalking.

Data privacy refers to the evolving relationship between technology and the legal right to, or public expectation of privacy in the collection and sharing of data about one's self. Privacy concerns exist wherever uniquely identifiable data relating to a person or persons are collected and stored, in digital form or otherwise. In some cases these concerns refer to how data is collected, stored, and associated. In other cases the issue is who is given access to information. Other issues include whether an individual has any ownership rights to data about them, and/or the right to view, verify, and challenge that information.

Various types of personal information often come under privacy concerns. For various reasons, individuals may not wish for personal information such as their religion, sexual orientation, political affiliations, or personal activities to be revealed. This may be to avoid discrimination, personal embarrassment, or damage to one's professional reputation.

Financial privacy, in which information about a person's financial transactions is guarded, is important for the avoidance of fraud or identity theft. Information about a person's purchases can also reveal a great deal about that person's history, such as places they have visited, whom they have had contact with, products they use, their activities and habits, or medications they have used.

Internet privacy is the ability to control what information one reveals about oneself over the Internet, and to control who can access that information. These concerns include whether email can be stored or read by third parties without consent, or whether third parties can track the web sites someone has visited. Another concern is whether web sites which are visited collect, store, and possibly share personally identifiable information about users. Tools used to protect privacy on the internet include encryption tools and anonymizing services like I2P and tor.