In [[Three-tier architecture|three-tier organization]], applications are structured around three physical tiers: client, application, and [[database]].<ref>{{cite web | url=http://msdn.microsoft.com/en-us/library/ff647546.aspx | title=Three-tiered distribution | author=Microsoft | access-date=2011-09-19 }}</ref><ref>{{cite web | url=http://download.oracle.com/docs/cd/E10316_01/cs/cs_doc_10/documentation/integrator/clustering_concepts_10en.pdf | title=clustering_concepts_10en | author=Oracle | access-date=2011-09-19}}</ref><ref>{{cite web | url= http://www.sis.pitt.edu/~perkoski/is1092/slides/chapter01.ppt | title=Introduction to Web Development | author=Robert R. Perkoski |archive-url=https://web.archive.org/web/20131107052241/http://www.sis.pitt.edu/~perkoski/is1092/slides/chapter01.ppt | archive-date=2013-11-07}}</ref><ref>{{cite web | url=http://publib.boulder.ibm.com/html/as400/v5r1/ic2933/index.htm?info/rzaii/rzaiithreetier.htm | title= Using Client Access Express in a three tier environment | author=IBM | access-date=2011-09-19}}</ref> The database is normally an [[relational database management system|RDBMS]]. The application contains the business logic, running on a server and communicates with the client using [[HTTP]].<ref>{{cite web | url=http://download.oracle.com/docs/cd/B25221_05/web.1013/b13593/undtldev010.htm | title=Understanding the Three-Tier Architecture | author=Oracle | access-date=2011-09-19}}</ref> The client on web applications is a web browser that runs HTML generated by the application layer.<ref>{{cite web | url=http://msdn.microsoft.com/en-us/library/aa905336.aspx | title=Pragmatic Architecture: Layering | author=Microsoft | access-date=2011-09-19}}</ref><ref>{{cite web | url=http://www.arokiait.com/3-tire-web-architechture.htm | title=3-Tier Web Architecture | author=Arokia | access-date=2011-09-19}}</ref> The term should not be confused with MVC, where, unlike in three-tier architecture, it is considered a good practice to keep business logic away from the controller, the "middle layer".<ref>{{cite web|url=http://www.arrangeactassert.com/asp-net-mvc-controller-best-practices-–-skinny-controllers/ |title=ASP.NET MVC Controller Best Practices |access-date=2011-09-19 |url-status=dead |archive-url=https://web.archive.org/web/20111011174215/http://www.arrangeactassert.com:80/asp-net-mvc-controller-best-practices-%E2%80%93-skinny-controllers/ |archive-date=2011-10-11 }}</ref><ref>{{cite web | url=http://weblog.jamisbuck.org/2006/10/18/skinny-controller-fat-model | title=Skinny Controller, Fat Model | author=Jamis Buck |archive-url=https://web.archive.org/web/20150516021854/http://www.arrangeactassert.com/asp-net-mvc-controller-best-practices-%E2%80%93-skinny-controllers/ | archive-date=2015-05-16}}</ref>
==Framework applications==
Frameworks are built to support the construction of internet applications based on a single programming language, ranging in focus from general purpose tools such as [[Zend Framework]] and [[Ruby on Rails]], which augment the capabilities of a specific language, to native-language programmable packages built around a specific user application, such as [[content management system]]s (CMS), some mobile development tools and some portal tools.<ref>{{Cite news|url=https://www.wired.com/2010/02/get_started_with_web_frameworks/|title=Getting Started With Web Frameworks|publisher=[[Wired Magazine]]|access-date=2018-04-02|language=en}}</ref>
