AppExchange is cloud computing marketplace of Salesforce.com. In AppExchange, Force.com platform hosts their apps to be sold, for the end users, who can access, download and install software apps. Salesforce AppExchange is a website, which has a mixture of free and paid apps. These apps are organized into collections, categories and industry solutions that enclose a variety of fields and also including small business and for customer service and for education and real estate. Salesforce AppExchange launched in 2005 and launched by Salesforce.com, and also it became the first public directory of its kind.

AppExchange apps are customized for Salesforce and extend Salesforce for every department and for every industry. AppExchange is more than business apps, where we can find its components, Lightning Data, Bolt Solutions, consulting partners, and developers that help us to extend the power of Salesforce. 

A brief description of Lightning Platform AppExchange works:

• Create: For improving the business a Salesforce user triggers the process by creating custom objects, and custom tabs, or set of dashboards and reports. Salesforce customers can share their customizations with other Salesforce users as an app or extension.
• Publish: A customer of Salesforce can register and publish an app on the AppExchange, and also the customer can create a demo of the functionality in the app for others to view before installing.
• Install: Installation of a published app from the AppExchange is safe and simple. And Only Salesforce administrator can select to install the app which is published on to the AppExchange.

[AppExchange - screenshot]