A soft credit is when a donor gives a gift, but another constituent, or multiple constituents, may have influenced the gift. You may want to track other constituents that are not getting the primary credit for the gift. An example is a gift from a husband and wife. If you record the gift on the husband’s record, you may want to add a soft credit on the wife’s record. 

Soft credits can be set up to happen automatically by creating a relationship between the two constituents. You can set up an auto soft credit to happen only when one constituent enters a gift, or when either enters a gift by ensuring the button is marked "yes" on both relationship records.