Third-party applications are a way to find and use business-specific functionality that may be needed as an add-on to the Salesforce platform. Think of Salesforce as similar to your iPhone or Android phone. While the platform is robust and delivers a lot of functionality out of the box, some things are not there and must be custom-built or installed as an add-on.
The job of an admin or business analyst is to perform a cost-benefit analysis to determine whether an organization should custom build functionality or decide to go with a third-party application. There are two types of third-party applications, managed and unmanaged. We will study them in the following sections.