Terms you'll need to understand:
One-tier
Two-tier
N-tier
ODBC
OLE-DB
Linked server
Remote server
Heterogeneous data
Replication
OPENROWSET
OPENQUERY
Automation
Job
Operator
Alert
SQL Server Agent
Techniques you'll need to master:
Application architecture design
ODBC and DSN creation
Distributed data access
Server connectivity
Automating SQL Server processes