Acts on the actual DB structure or on the data (although without handling data), depending on the nature of the query and the database. The SQLBuilder tool helps you write easily your SQL statements.
The tPostgresqlRow is the specific component for the database query. It executes the SQL query stated onto the specified database. The row suffix means the component implements a flow in the job design although it doesn't provide output.
For more technologies supported by Talend, see Talend components.