Frequency is the number of times content is shown to the same person.
Presenting content to the same person multiple times is something that advertisers do regularly across many different types of media. Many digital marketing platforms track frequency, use it to build brand awareness, and to expose customers to your content in a way that helps them remember it. Frequency has a sweet spot. If the number is too low, your marketing plan will not be effective as it could be. If the number is too high, you are wasting money on people that have already been exposed to your content.
Frequency is calculated by taking the amount of Impressions and dividing them by Reach.