There are only a few places to implement performance gains in an application – the presentation layer, the application layer, and the storage layer.

在一个应用程序中仅有几个地方能够实现性能增益 - 表示层、应用层和存储层。

youdao

Configuration Major layers of the application — in the RentaBike application, I expose a Data Access Object (DAO) layer, a controller layer, and a view layer (see Listing 1).

配置应用程序的主要层——在RentaBike应用程序中，我公开了一个数据访问对象(dao)层、一个控制器层和一个视图层(参阅清单1)。

youdao

Application layer: The application layer is used by most programs that require network communication.

应用层：这里主要是需要进行网络通信的应用程序。

youdao

OpenMobile is a new company on the application compatibility scene whose primary product, the Application Compatibility Layer, promises to bring Android's large volume of apps to smaller platforms.

ENGADGET: OpenMobile demos ACL for MeeGo, promises 100 percent compatibility with Android apps (video)

The application layer might be comparable in both cases, but the OSes are not.

CNN: Sendmail brings open source technology from Unix to NT

The real carrot is the managed services and software on top of a Cloud platform and application layer.

FORBES: Rackspace: Bull and Bear Cases