The Community addition is the full LoadRunner installation.
The standalone components includes the packages of the TruClient, Analysis and Vugen stand alone installations which are subsets of the LoadRunner isntallation
The additional components are not included in the above and includes the following components that LoadRunner's users might need:
Agent for Citrix Server
Agent for Microsoft Terminal Server
HostID generator
HP NV
IDE Add-Ins
Protocol SDK
Mobile Remote Agent
SAP tools
VTS
other 3rd party components