A district judge is a type of judicial officer who presides over cases in a specific geographic area or jurisdiction. They are appointed by the president and confirmed by the Senate, and they typically serve for life tenure. District judges have various responsibilities including hearing both civil and criminal cases, conducting trials, and making rulings on legal matters brought before them. In some instances, district judges may also be involved in sentencing or other post-trial proceedings. Overall, the role of a district judge is to uphold the law and provide justice within their jurisdiction.