Use when your question is about one of the versions of the ArcGIS Pro application of ArcGIS Desktop
The community decided against creating tags for each dot release of ArcGIS Pro 1.x - see http://meta.gis.stackexchange.com/questions/4280/are-version-tags-needed-for-arcgis-pro
ArcGIS Pro is an application of ArcGIS Desktop which was first released as part of ArcGIS 10.3.
Using ArcGIS Pro, you can visualize, edit, and analyze your geographic data in both 2D and 3D. After you create projects, maps, layers, tools, and more, ArcGIS Pro has several options for sharing your work with others.
Version 1.0 was released in January, 2015.