Lookalike Audiences are used to:

Lookalike Audiences are a powerful targeting tool that allows advertisers to expand their reach by finding new users who are likely to be interested in their products or services. They are created by taking a "seed" audience (e.g., existing customers, website visitors) and then identifying other users on the platform who share similar demographic, behavioral, and interest-based characteristics. Targeting users who have already purchased your product is incorrect because this describes retargeting, not lookalike audiences. Targeting users based on their location and demographic information is incorrect because this describes demographic and geographic targeting, which can be part of a lookalike audience's characteristics but isn't the primary purpose. Retargeting users who have abandoned their carts is incorrect because this is a specific form of retargeting, not lookalike audience creation.