The sources of conflict are many, but you can put them all under two broad headings. Conflict of ideas, and Behavioural conflict.
Conflict of ideas is common, and it means that you do not agree with the others opinion, plan or proposal. In order to manage this type of conflict you need to develop your communication skills to make yourself more persuasive.
Behavioural Conflict is when the other person is doing things you don’t want them to do, (or failing to do things they should do). Then you have to use your communication skills to do some “behaviour modification”. Modifying another person’s behaviour using only your words, is not an easy thing to do, but you will learn how to do it on this course.