gerund / present participle
The -ing form as a noun versus the -ing form as a verb or an adjective.
A gerund is the -ing form used as a noun: Filing took an hour. A present participle is the same form used as a verb or as an adjective: She is filing. The filing clerk left. The ending is the same. The job in the sentence is not.
Examples
Use Waiting tired her. (gerund)
Use She is waiting. (present participle)