The connection between copyright law and fair use practices typically depends on the copyright laws of a given country or area. In general, however, fair use is an aspect of copyright laws and may be either explicitly or implicitly indicated by those laws. Copyright laws in the US, for example, indicate a number of parameters used to determine when fair use of a copyrighted work has been made, rather than infringement upon a legal copyright.
Copyright law and fair use practices are both generally outlined in the various laws and court cases that have established fair usage in the US. A copyright is a form of legal ownership over a particular work of art or creation, often protecting that work from unapproved use or recreation by others. Fair use refers to the usage of a copyrighted work, usually without the permission of the copyright owner, that is not considered in violation of that copyright. This means that copyright law and fair use laws are closely connected, though fair use is not necessarily a loophole in copyright protection.
There are typically a number of ways in which copyright law and fair use practices are established and governed within a country. In the US, for example, copyright laws have largely been established through a number of different laws and upheld or modified through various court cases. These cases and laws have established how a copyright is created, who owns that copyright, how long it lasts, and how others may legally use the copyrighted work. Copyright law and fair use practices in the UK have been established and defined by the Copyright Designs and Patents Act of 1988; fair use, or fair dealing, laws in the UK could, therefore, be different than in the US.
In many countries there is no precise and clearly evident way to ensure that a work is being used through fair use practices, rather than infringement, though there are some guidelines. If a work is being used for nonprofit educational purposes by a teacher or student, is used only in part, and is not used in a way that affects the commercial viability of the work, then it is likely being used fairly, depending on the nature of the work. Copyright law and fair use practices are strongly intertwined, since one often defines the other, but since such laws depend on particular countries, care should be taken by anyone using a copyright to ensure fair use practices are upheld.