Salesforce1 is Salesforce's mobile application and development platform. It was originally released in 2012 as a mobile version of Chatter and was transformed into the Salesforce1 mobile app in 2013. In 2014, Salesforce introduced the Lightning framework. Lightning provides tools like Lightning Connect, Process Builder, and App Builder that allow non-technical or technical users to build mobile apps and connect data sources through a visual, point-and-click interface. It also includes a set of Lightning Components that can be used to customize apps along with mobile SDKs for building native and hybrid mobile applications.