What is a gerund?
When the root form of verb is joined with a ‘ _ing’, the verb is known as a gerund. At times, they can even act as nouns and can become the subject or object of a sentence.
Jogging is good for health.
You can see in the above example that, ‘jogging’ (like a noun) is the subject of the sentence, but at the same time it also has an object (like a verb), and this object is ‘health’. This is why a gerund is called a verbal noun, or a noun that has the qualities of a verb.