A more thorough explanation:

The fourth estate refers to the profession of journalism and the news media. The term originated from the British Parliament's reporters' gallery, which was considered to have the same level of influence as the three traditional estates of Parliament: the Lords Spiritual, the Lords Temporal, and the Commons. In France, the three estates were the clergy, the nobility, and the commons.

For example, when a journalist reports on a political scandal, they are acting as a member of the fourth estate. Their job is to inform the public about important events and hold those in power accountable for their actions. The fourth estate plays a crucial role in a democratic society by providing citizens with the information they need to make informed decisions.