While parliamentary democracy in India, as a political ideal, is still exposed to hazards arising from the attitudes of certain political parties and criticisms from others, the mechanism of the system functioning through Parliament is being progressively perfected. The mechanism can be an important factor contributing to the success of the system, but it cannot be the sole factor. A parliamentary system is a system of democratic governance of a state in which the executive branch derives its democratic legitimacy from, and is held accountable to, the legislature (parliament); the executive and legislative branches are thus interconnected. In a parliamentary system, the head of state is normally a different person from the head of government. Parliament is becoming a more effective instrument for expressing public opinion and voicing public grievances. It is also becoming increasingly effective in restraining the executive and ensuring the latter's response and accountability to national sentiment and will, which finds expression in a broad manner in the House through elected representatives of organized political parties and others. This is in contrast to a presidential system in a democracy, where the head of state often is also the head of government, and most importantly, the executive branch does not derive its democratic legitimacy from the legislature.