The data that apps use to track you, according to Apple

Apple this week posted new privacy "nutrition labels" on apps in the iOS App Store, giving users a look at how different apps stack up according to Apple's standards.

The big picture: The labels show that generally, social media apps collect more kinds of data than messaging apps.

• Messaging apps owned by Facebook, like Whatsapp and Messenger, appear to collect more data than some of their peers, per Apple's labeling standards.
• Signal, which is run by a privacy-focused non-profit, collects virtually no data from its users.

The big picture: The labels are meant to serve as an easy-to-view summary of how apps collect user data for users to review before they install a new app.

• Apple does post privacy labels for its own apps, like Messages, but they do not appear in the App Store, since these apps are pre-installed. A user has to find the labels on the web separately.

Yes, but: Some developers, like Facebook's messaging service WhatsApp, worry that the summaries are too broad and could spook users into thinking they collect more data than they do.

• The labels are one part of a larger battle between Apple and Facebook over Apple's efforts to tighten privacy rules, which Facebook argues could harm small businesses who benefit from ad tracking.
• "We believe users should have the choice over the data that is being collected about them and how it’s used," Tim Cook tweeted Thursday. "Facebook can continue to track users across apps and websites as before, App Tracking Transparency in iOS 14 will just require that they ask for your permission first."

Details: Apple identified a set of data types including purchases, financial information, location, contact information, diagnostics, search history, health & fitness, browsing history, and more. An app may collect each of these types of data in three ways:

1. "Data linked to you" is data that is tied to a users' identity via information from their device, account on an app, and other sources.
2. "Data used to track you" is data that links user or device data collected from an app with user or device data collected from other companies’ apps or websites for the purpose of targeted advertising or ad measurement. It could also refer to sharing user or device data with data brokers.
3. "Data not linked to you" is data that cannot be linked to the user in any identifying way.

Between the lines: It's helpful to know the number of data types an app collects from you, but that doesn't give you any insight into the actual volume of data the app may be collecting.