This expression, which alludes to being in a position at the front of a mass of troops rushing towards the enemy in battle, is used figuratively to refer to someone or something at the forefront of a concerted effort to achieve a difficult task or goal. Those 'leading the charge' are the first to be exposed to risk and danger, and their example is designed to motivate and inspire others to follow. It is most commonly used in a professional context where the concept of leading your department, company, or industry towards a certain goal or direction is quite prevalent.