Second-party data is a term used in the context of digital marketing and advertising to refer to data that is collected by one organization and shared with another organization, for the purpose of targeting and personalizing advertising. Second-party data can be an effective way for organizations to access high-quality, relevant, and actionable data, without the need to collect and manage the data themselves. Second-party data can be sourced from a variety of sources, such as publishers, data brokers, or other organizations, and can be used to target and personalize advertising based on a wide range of factors, such as location, demographics, behaviors, or other characteristics. Second-party data can be an important part of an advertiser's media planning and buying strategy, as it can provide access to a wealth of data and insights, and can help to optimize and improve the performance of their advertising efforts.