what is a datastore

Datastore is the citrix database which stores all the static information including the following

-Farm Configuration
-Published application configuration
-Metaframe administration accounts
-Server configurations
-Printer configurations
-Trust relationships

another answer to the above qn
Its a database that has info of citrix farm like Xenapp server, Data collector, Zone, Citirx policies, printers, license server, ports etc.....it provide this info to all citrix xenapp server in a for