The website and app you use can collect information about your online activities, such as which websites or apps you visit, what device you use, and even your browsing behavior. This information is stored or read on your device to recognize it each time you connect to an app or a website.
Advertisements shown on the service can be based on limited data, such as the website or app you are using, your non-precise location, your device type, or which content you are (or have been) interacting with. This information is used to present advertising that appears more relevant to you based on your possible interests.
Your activity on the service can be stored and combined with other information about you from previous activities on the service or other websites and apps. This information is then used to build a profile about you, which might include possible interests and personal aspects. Your profile can be used later to present content that appears more relevant based on your possible interests.
Content presented on the service can also be based on your content personalization profiles, which reflect your activity on this or other services. This information is used to adapt the order in which content is shown to you, making it easier for you to find (non-advertising) content that matches your interests.
Information about your interactions with advertising and content can help determine how well an ad has worked for you or other users and whether the goals of the advertising were reached. This information also helps understand the relevance of non-advertising content, such as articles, videos, podcasts, or product descriptions.
Reports can be generated based on data sets from user profiles, statistics, market research, and analytics to identify common characteristics among users. This information is used to improve products and services, build new ones, and develop advertising campaigns that are more effective.
Your device’s information, such as its IP address or browser type, helps ensure the technical compatibility of content and advertising. It also facilitates the transmission of content or ads to your device.
When you make choices about how personal advertising is presented to you, these preferences are saved in cookies or stored on your device for a specific duration. The duration varies depending on whether it’s a website, app, or accelerated mobile page (AMP) site.
Source: https://bigthink.com/starts-with-a-bang/how-large-biggest-galaxy-universe