What is licensing as a noun?

The noun 'licensing' is a gerund, the present participle of the verb to license that functions as a noun.

The present participle of the verb also functions as an adjective.

Examples:

Licensing is required to operate a motor vehicle on public roads. (noun, subject of the sentence)

Which agency is licensing casinos in our state? (verb)

The licensing agency is located in city hall. (adjective)