辅助 (fǔzhù) as a verb means 'to assist' — it's slightly more formal and task-oriented than 帮助 (bāngzhù), often used in technical or systematic contexts (e.g., assisting a professor in a lab). As an adjective it means 'supplementary, auxiliary' (e.g., auxiliary equipment), a sense that 帮助 lacks. 协助 (xiézhù) is closer but implies collaborative teamwork; 辅助 can describe a supporting role in a system or process.