There are different ways to target your audience.
The possibilities to target audiences are exciting. There are three ways in which you can use targeting on YouTube:
Keywords: Keywords work like a regular Google search. Someone types in a keyword you want to rank for and your ad will be shown.
Placements (videos, channels): With Placements, you can run your ad in front of a dedicated video or on a channel — for example, from an important influencer of your niche or your competitor.
Audiences (affinity and in-market): Affinity and in-market audiences are ready-to-use audiences by Google. With affinity audiences, you reach people based on their specific interests. With in-market audiences, you reach people who actively research or compare products and services across the Google network.
You can use one way to target your audience or all of these possibilities together to create a highly relevant target for your ad.