SQL Server process queries on the server rather than on the client. The SQL
statement is sent to the server where it is processed and only matching
records and fields are returned across the network to the client. Access
process the query on the client. Depending on indexes and lots of other
factors, much more network traffic is generated.
Other points regarding SQL Server:
-has more robust security
-can authentic users based on their network login
-supports triggers
-can be much larger
-can handle many more users
-can be programmed with stored procedures and user defined functions
-software costs more (relative) but can be a much better investment
-has DTS which is awesome
-much much more
-doesn't have forms and only recently has a decent reporting tool been made
available
http://www.microsoft.com/sql/reporting/default.asp