Every time you cut and paste or 'share' something online you are using other people's copyright material. Text, images, music and video found online is not copyright free and doesn't need a copyright notice for protection. Copyright generally lasts for the life of the creator plus 70 years. Just because you change something or cite the source doesn't mean you can use it. For anyone working in tourism, an understanding of copyright can help you decide when you can rely on a licence or an exception and when you need to get permission from the copyright owner.
Copyright also protects your own work. As a student, you own copyright in material you create, unless you have signed a copyright transfer or you are an employee creating something for your workplace. If you are a researcher, you own copyright in your thesis and research, unless it is a collaborative research project. See University Copyright page.