The Bill of Rights applies to all laws. It must be followed by all branches of government and all government bodies. This means it must be followed by:
(See: The Separation of Powers)
The Bill of Rights applies to all matters between citizens and the government. This means it applies in a vertical way between government and citizens. It protects citizens from things done to them by the government.
The Bill of Rights also works in a horizontal way. This means it applies to matters between ordinary people. It protects people from things done to them by other people.
Examples:
In both these examples each person has rights. The question is, whose rights are more important in the circumstances and whose rights should be protected? The Bill of Rights protects people from having their rights abused by another person (in other words, it works in a horizontal way) but sometimes it is difficult to know whose rights are more important in each case. Ultimately, it will be up to the courts to decide whose rights should be protected.