Bad Academic Practice (which include plagiarism) and Good Academic Practice can be understood in terms of Academic Integrity, expressed as the six fundamental values of honesty, trustworthiness, fairness, respect, responsibility, and courage (source: International Center for Academic Integrity). These values underpin the teaching and research undertaken by universities.
Referencing is essential for acknowledging the sources you have used in your work, and for avoiding a charge of plagiarism.
Plagiarism is an academic offence, and is defined by Chapter 4 Academic offences and bad academic practice of the University Student Regulations as 'the significant use by a student of other people's work and the submission of it as though it were is or her own'. You can avoid plagiarism with correct referencing.
Below is the guidance on plagiarism from Cite Them Right:
Good referencing is integral to good academic practice but developing good academic practices involves much more.
DMU Good Academic Practice map: a visual interactive map providing information and links to resources to help you do your work in a way that meets the highest standards.