Soft Money
When cash is contributed to a political party with no limits attached to the amount that can be received, this is known as a "soft money" contribution. The funds can come from individuals and political action committees as with "hard money", but they can also come from any other source, such as corporations. The law says that this money can only be used for "party-building activities" such as advocating the passage of a law and voter registration, and not for advocating a particular candidate in an election.
Hard Money
When cash is contributed directly to a political candidate, it is known as a "hard money" contribution. These contributions may only come from an individual or a political action committee, and must follow the strict limits set forth by the FEC. For example, in 2012, the maximum amount that an individual can contribute to a presidential candidate or committee