First, let me say that I am a registered Lobbyist but that is not my full-time job. I take on select efforts that I feel are important; for example, I helped push the JOBS ACT.
Lobbyists are simply people or organizations that attempt to influence lawmakers. A Lobbyist is required to become registered when they donate more than $5,000 to a politician.
There are many types of Lobbyists.
Labour organizations, trade organizations, and Unions are the most common and lobby for laws that affect organizations.
There are professional Lobbyists that will lobby for a fee.
While lobbying gets a bad name and some groups deserve the bad press; it is a necessary part of our political system.