This is the place where all the static information are stored. The Data Store provides a repository of persistent information about the farm (Farm configuration information, Published Application configurations, Server configurations, Static policy configuration, XenApp administrator accounts, and Printer configurations) that all servers can refer.
The data store is the central repository where almost the entire Citrix implementation is invested. The Administrators of the farm, the license server to point to, the whole farm configuration, the published applications, all their properties, the security of who gets access to what, the custom load evaluators, custom policies, configured printers and print drivers, all this is stored in the central repository called the Data Store.

Data Collector stores all the dynamic information like session, load and published applications in the servers in their zones and communicates the zone information to the Data Collectors in other zones in the farm.
Data collector is a Citrix Presentation Server whose IMA service takes on the additional role of tracking all of the dynamic information of other Presentation Servers. This information is stored in memory and called the “dynamic store”.

The data store is a database on disk. The dynamic store is information stored in memory.
To look the contents of the in-memory dynamic store on the data collector, use “queryds” command. QueryDS can be found in the “support\debug” folder of your Presentation Server installation source files.
To determine which server is acting as the data collector in the zone run “query farm /zone” from the command line