Sitecore xDB, the Experience Database, is the data store behind Sitecore XP. It records visitor interactions such as page views, goals and campaign activity, and keeps them in a contact profile.
Marketers use this data for analytics, segmentation and personalization. Each visit adds to a picture of how people use your site over time.
xDB belongs to the XP architecture. Newer SaaS products such as Sitecore CDP and Personalize cover similar needs in the cloud.
For help with data, tracking and platform choices, see our Sitecore expertise.