Aggregate data refers to information that has been combined from multiple sources or individuals to form a collective summary or overview.
It details how an entire group of consumers interacts with your marketing efforts or websites.
For example, this could be data about how the audience views videos, ads & pictures, the actions they take after viewing, etc.
It gives a comprehensive view of how your target market is engaged as a whole, through your marketing efforts, as opposed to individualised consumer data.