To sponsor something is to support an event, activity, person, or organization financially or through the provision of products or services. A sponsor is the individual or group that provides the support, similar to a benefactor.
Sponsorship is a cash and/or in-kind fee paid to a property (typically in sports, arts, entertainment or causes) in return for access to the exploitable commercial potential associated with that property, according to IEG.

While the sponsee (property being sponsored) may be nonprofit, unlike philanthropy, sponsorship is done with the expectation of a commercial return.

And, while sponsorship can deliver increased awareness, brand building and propensity to purchase, it is different than advertising.