If you are not familiar with AppExchange, it is a business app store hosted by Salesforce.com for Salesforce users. You can find thousands of apps to be installed into your Salesforce instance to meet or enhance your business needs. Some of the apps are free, while many have a license fee. They are built by Salesforce partners. In addition, there are some sample apps that have been provided by Salesforce Labs. Salesforce Labs does not support the apps they post on the AppExchange, but it offers many examples of Salesforce features that help admins learn how to use these features.
The app installed from AppExchange is considered a third-party app, which means it is not supported by the Salesforce Support team. For paid apps, usually, the developer will provide their support for their app.