Charitable donations can fall under both categories. Note that the “categories” I spoke of are just what is used colloquially. The USA tax code doesn’t really distinguish all these tax deductions into two neat groups.

A charitable donation can take the form of a business expense, say if a local welding supplier pitches in $100k to sponsor a regional vocational technology fair. They get to be a “platinum sponsor” and a spokesperson will speak during the event, so maybe some of that expense is actually marketing dollars and not purely philanthropic. The tax code may have specific rules, but most donations of this sort tend to be allowed.

Likewise, a charitable donation can be a way to extract a little bit of value from something near worthless. For example, fine art is known to be ripe for abuse in this way, where the donation of the artwork means the “market value” can be written off. But that market is easily distorted, and valuations can vary tremendously. Another example is the donation of development rights, whether or not a development was even possible under the zoning laws at play.

Charitable contributions can qualify as tax deductions because it’s viewed as good policy, after balancing the upsides with the loss of government revenue. But some are clearly better policies than others.