Lobbying is the practice of private advocacy with the goal of influencing a governing body, in order to ensure that an individual's or organization's point of view is represented in the government. A lobbyist is a person who is paid to influence legislation as well as public opinion. A more tactful description might be said to be someone who is engaged in public affairs.
Most major corporations and political interest groups hire professional lobbyists to promote their interests as intermediaries; others maintain in-house government or public relations departments. Think tanks aim to lobby through regular releases of detailed reports and supporting research to the media for dissemination .
A separate form of lobbying, called "outside" lobbying or grassroots lobbying, seeks to affect the legislature or other bodies indirectly, through changing public opinion (or purporting to — fake grassroots campaigns are known as astroturfing). A modification of the same, aimed to leaders and influential persons in the community, is known as grasstops.
Lobbying is in many countries a regulated activity, with limits placed on how it is conducted, in an attempt to prevent political corruption. In the United States for example, lobbyists must be registered unless they represent an elected official, or an organization of elected officials, such as the National Governors Association.