Which tool can be used to integrate third-party applications into Salesforce?

Salesforce AppExchange is the correct tool for integrating third-party applications into Salesforce. It serves as an online marketplace where users can discover, install, and leverage a wide variety of applications that have been developed specifically to work with the Salesforce platform. These applications can range from simple plugins that enhance existing functionality to complex solutions that provide entirely new capabilities.

The integration process via AppExchange is streamlined and user-friendly, significantly reducing the technical barriers typically associated with third-party integrations. This marketplace is rich with solutions created by independent software vendors (ISVs), allowing businesses to tailor Salesforce to meet their unique needs without the need to develop custom applications from scratch.

While other options listed might suggest certain functionalities related to Salesforce, they do not serve the same purpose as AppExchange in terms of providing a robust environment for third-party application integration.