In general, a framework is a real or conceptual structure intended to serve as a support or guide for the building of something that expands the structure into something useful.
In computer systems, a framework is often a layered structure indicating what kind of programs can or should be built and how they would interrelate. Some computer system frameworks also include actual programs, specify programming interfaces, or offer programming tools for using the frameworks. A framework may be for a set of functions within a system and how they interrelate; the layers of an operating system; the layers of an application subsystem; how communication should be standardized at some level of a network; and so forth. A framework is generally more comprehensive than a protocol and more prescriptive than a structure.
Examples of frameworks that are currently used or offered by standards bodies or companies include:
- Resource Description Framework, a set of rules from the World Wide Web Consortium for how to describe any Internet resource such as a Web site and its content.
- Internet Business Framework, a group of programs that form the technological basis for the mySAP product from SAP, the German company that markets an enterprise resource management line of products
- Sender Policy Framework, a defined approach and programming for making e-mail more secure
- Zachman framework, a logical structure intended to provide a comprehensive representation of an information technology enterprise that is independent of the tools and methods used in any particular IT business
The designers of software frameworks aim to facilitate software developments by allowing designers and programmers to devote their time to meeting software requirements rather than dealing with the more standard low-level details of providing a working system, thereby reducing overall development time. For example, a team using a web framework to develop a banking website can focus on writing code particular to banking rather than the mechanics of request handling and state management.
Frameworks often add to the size of programs, a phenomenon termed “code bloat”. Due to customer-demand driven applications needs, both competing and complementary frameworks sometimes end up in a product. Further, due to the complexity of their APIs, the intended reduction in overall development time may not be achieved due to the need to spend additional time learning to use the framework; this criticism is clearly valid when a special or new framework is first encountered by development staff. If such a framework is not used in subsequent job taskings, the time invested in learning the framework can cost more than purpose-written code familiar to the project’s staff; many programmers keep copies of useful boilerplate for common needs.
However, once a framework is learned, future projects can be faster and easier to complete; the concept of a framework is to make a one-size-fits-all solution set, and with familiarity, code production should logically rise. There are no such claims made about the size of the code eventually bundled with the output product, nor its relative efficiency and conciseness. Using any library solution necessarily pulls in extras and unused extraneous assets unless the software is a compiler-object linker making a tight (small, wholly controlled, and specified) executable module.
The issue continues, but a decade-plus of industry experience has shown that the most effective frameworks turn out to be those that evolve from re-factoring the common code of the enterprise, instead of using a generic “one-size-fits-all” framework developed by third parties for general purposes. An example of that would be how the user interface in such an application package as an office suite grows to have common look, feel, and data-sharing attributes and methods, as the once disparate bundled applications grow unified into a suite which is tighter and smaller; the newer/evolved suite can be a product that shares integral utility libraries and user interfaces.
This trend in the controversy brings up an important issue about frameworks. Creating a framework that is elegant, versus one that merely solves a problem, is still an art rather than a science. “Software elegance” implies clarity, conciseness, and little waste (extra or extraneous functionality, much of which is user defined). For those frameworks that generate code, for example, “elegance” would imply the creation of code that is clean and comprehensible to a reasonably knowledgeable programmer (and which is therefore readily modifiable), versus one that merely generates correct code. The elegance issue is why relatively few software frameworks have stood the test of time: the best frameworks have been able to evolve gracefully as the underlying technology on which they were built advanced. Even there, having evolved, many such packages will retain legacy capabilities bloating the final software as otherwise replaced methods have been retained in parallel with the newer methods.