Ethics is a vital part of a humans moral code. In all most every job or situation there are choices to be made. These choices will be made/ determined based on your moral code. things happen in day to day life that frequently make us question our own moral and ethically points of view.
What is morally correct? what is the moral thing to do? would we do this based on our own principles? etc.
As a journalist, it is key to having good ethics as it helps to build a strong reliable reputation. This reputation follows them around and is what people know the journalist for. Having a good reputation can help journalists gain better sources, job changes, and other employments. If a journalist makes a bad ethical decision then this will affect their credibility and could affect their line of work from sources to viewership, to other employments.