The act of ~ is ~ (rare, difficult, easy, important, etc.). Expresses the meaning that something is rare, difficult, easy, important, etc.日本語を話すことは難しいです。
Verb in て-form + いますN3
In the process of ~; Have ~ (and the state still continues). Expresses an ongoing action or a prolonged state.私は今、昼ご飯を食べています。