Copyright is an important issue and understanding how the law works is essential in HE because as users, producers and disseminators of information we need to maximise our ability to exploit the value in our own work. We also need awareness in order to minimise the risk of infringement and the consequent liability towards others.
For an explanation of the Basics of Copyright Law, this video from West Valley College helps to explain the main concepts you need to be familiar with - just be aware that in the UK our concept of 'fair use' is called 'fair dealing'.