The following four layers are the most common layers in a logical multilayered architecture for an information system with an object-oriented design:
- Presentation Layer (a.k.a. UI Layer, View Layer, Presentation Tier.)
- Application Layer (a.k.a. Service Layer or GRASP Controller Layer )
- Business Layer (a.k.a Business logic layer (BLL))
- Infrastructure Layer (Data access layer, Persistence layer, Logging, Networking, and other Services which are required to support a particular Business Layer.)
Some common purposes of the above four layers are for example described in the book about domain-driven design at page 68-74, which is a book that otherwise is focused on describing the Domain layer
Sometimes there is no explicit distinction between the Business Layer and the Application Layer, e.g. the Application Layer is considered as being a part of the Business Layer. On the other hand, it is also possible to even further divide the Application/Business Layers into more layers. For example, if the Model View Presenter pattern is used, then you can consider the Presenter Layer as being a layer between the User Interface Layer and the Application Layer.
The Business Layer can also use a Business Infrastructure Layer (aka low-level business 'services' layer) logically positioned between Business Layer(s) and Infrastructure Layer(s). That layer (BI) is very general and can be used in several application tiers, e.g. a CurrencyConverter.
The Infrastructure Layer may be partitioned into different levels (high-level or low-level technical services). Though, it is not unusual that developers only consider the persistence (data access) and therefore only talk about the Persistence Layer or the Data Access Layer (instead of an Infrastructure Layer or Technical services Layer). In other words, the other kind of technical services are not always being explicitly thought of as being part of any particular layer.
Regarding that all types are not always considered as belonging to one particular layer, according to the "POSA book" (Pattern-Oriented Software Architecture A System of Patterns, page 39) a relaxed layered system (as opposed to a strict layered system) can use so called "shared data definition modules" which are types not belonging in a particular layer.
Famous quotes containing the words common, layers, information, system, logical and/or architecture:
“Civil servants and priests, soldiers and ballet-dancers, schoolmasters and police constables, Greek museums and Gothic steeples, civil list and services list—the common seed within which all these fabulous beings slumber in embryo is taxation.”
—Karl Marx (1818–1883)
“The force of a death should be enormous but how can you know what kind of man you’ve killed or who was the braver and stronger if you have to peer through layers of glass that deliver the image but obscure the meaning of the act? War has a conscience or it’s ordinary murder.”
—Don Delillo (b. 1926)
“But while ignorance can make you insensitive, familiarity can also numb. Entering the second half-century of an information age, our cumulative knowledge has changed the level of what appalls, what stuns, what shocks.”
—Anna Quindlen (b. 1952)
“Psychoanalysis is an attempt to examine a person’s self-justifications. Hence it can be undertaken only with the patient’s cooperation and can succeed only when the patient has something to gain by abandoning or modifying his system of self-justification.”
—Thomas Szasz (b. 1920)
“There is no logical reason why the camel of great art should pass through the needle of mob intelligence.”
—Rebecca West (1892–1983)
“Art is a jealous mistress, and, if a man have a genius for painting, poetry, music, architecture or philosophy, he makes a bad husband and an ill provider.”
—Ralph Waldo Emerson (1803–1882)