... impact on whether users can be authenticated or authorized, but physical tiers canbe used to increase or decrease physical access to the machines on which the application executes.For instance, ... dataaccess code into a specific layer, the impact of these changes is limited to a smaller part of theapplication.Data access mechanisms are typically implemented as a set of services, with each ... How physical n-tier architectures impact performance, scalability, security, and faulttolerance• The difference between data-centric and object-oriented application models• How object-oriented...