It is more important to have less plagiarism in your report. We often refer journal and articles to do our research work and we are not sure whether these papers have been used by the students. if you copy any content from those article, then it will be counted against the plagiarism. No colleges will allow students who have plagiarism more than 20 percent. Even though you can argue that you have just used the concept, it will make them to feel bad impression on you and you will get less mark than expected. And most of the cases student will not be able to get their degree if the plagiarism level is more than prescribed. If you have not submitted your dissertation then you will be given a chance to do that but if you have submitted the one which has more copied content then it will be disastrous on your credit.
You will get no mark for your work. You will be failed on that specific subject and also you will not be able to get the degree certificate. If you are enrolled for master degree, but your dissertation has more copied content then you will only be given diploma certificate.
In case of international student it is very difficult to extend their study visa. This is because of the reason that, you need UCAS number to extend your stay as a student but the university or collect will not provide the one because of copied dissertation. It is important to take extra care when you do your assignments. Be good and get excellent marks.