One of the fields on the New Gift Form is "Passthrough Giver." A Passthrough Giver is an individual who should receive credit for a particular gift, even though the gift in question technically comes from another entity. Common examples might include business owners who give corporate gifts through their company instead of giving privately, or givers whose gifts come from a donor-advised fund. In these cases, while your nonprofit would receive checks from a company or community foundation, the intent to give actually originated with an individual.
When viewing the Giving tab in a Contact record, you'll notice that there is no add button for Passthrough gifts. Passthroughs cannot be entered directly or by themselves; a Passthrough is an element of an actual gift.
In some cases, you may want to split a single gift among multiple Passthrough Givers. For example, this is a common necessity for organizations who receive CFC gifts via the United Way. Since the Passthrough amount is always equal to the gift amount, for these situations, the best option is to split the gift into multiple gifts, entering a separate Passthrough for each gift.