Salesforce1 is a platform that enables application development and data exchange through application programming interfaces (APIs) and prebuilt programming code components.
Launched in November 2013, the principles underlying Salesforce1 are a mobile-first approach to application development, where applications are developed for the Web first and desktops second, and an open architecture that enables the Salesforce platform to work relatively easily with third-party apps.
Salesforce1 enables the building of applications in the Salesforce Customer Success Platform, in conjunction with the Lightning development platform. The combination also allows for third-party applications to be built on top of Salesforce apps for smartphones, tablets and wearables.
With Lightning, admins can create applications quickly and easily without having to code from scratch, because many items can draw on prebuilt Lightning Components. Salesforce1 also enables developers to use alternatives to Force.com, including the Heroku platform, through capabilities like Salesforce1 Heroku Connect, which make it easier to build customer-facing apps. Force.com has traditionally been used for creating internal employee-facing apps built on the Salesforce platform.
Open APIs also enable multiple applications built on different code bases to interact without conflict and share data. Salesforce1 involves the mobile app, which delivers the Salesforce platform as mobile apps, such as the Sales, Service, Community and Wave Analytics clouds. The Salesforce App Exchange also features third-party applications that have been built on top of the Salesforce platform.