Web application
View on Wikipedia
This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages)
|

A web application (or web app) is application software that is created with web technologies and runs via a web browser.[1][2] Web applications emerged during the late 1990s and allowed for the server to dynamically build a response to the request, in contrast to static web pages.[3]
Web applications are commonly distributed via a web server. There are several different tier systems that web applications use to communicate between the web browsers, the client interface, and server data. Each system has its own uses as they function in different ways. However, there are many security risks that developers must be aware of during development; proper measures to protect user data are vital.
Web applications are often constructed with the use of a web application framework. Single-page applications (SPAs) and progressive web apps (PWAs) are two architectural approaches to creating web applications that provide a user experience similar to native apps, including features such as smooth navigation, offline support, and faster interactions.
Web applications are often fully hosted on remote cloud services, can require a constant connection to them, and can replace conventional desktop applications for operating systems such as Microsoft Windows, thus facilitating the operation of software as a service as it grants the developer the power to tightly control billing based on use of the remote services as well as vendor lock-in by hosting data remotely. Modern browsers such as Chrome offer sandboxing for every browser tab which improves security and restricts access to local resources. No software installation is required as the app runs within the browser which reduces the need for managing software installations. With the use of remote cloud services, customers do not need to manage servers as that can be left to the developer and the cloud service and can use the software with a relatively low power, low-resource PC such as a thin client. The source code of the application can stay the same across operating systems and devices of users with the use of responsive web design, since it only needs to be compatible with web browsers which adhere to web standards, making the code highly portable and saving on development time. Numerous JavaScript frameworks and CSS frameworks facilitate development.
History
[edit]The concept of a "web application" was first introduced in the Java language in the Servlet Specification version 2.2, which was released in 1999. At that time, both JavaScript and XML had already been developed, but the XMLHttpRequest object had only been recently introduced on Internet Explorer 5 as an ActiveX object.[citation needed] Beginning around the early 2000s, applications such as "Myspace (2003), Gmail (2004), Digg (2004), [and] Google Maps (2005)," started to make their client sides more and more interactive. A web page script is able to contact the server for storing/retrieving data without downloading an entire web page. The practice became known as Ajax in 2005. Eventually this was replaced by web APIs using JSON, accessed via JavaScript asynchronously on the client side.
In earlier computing models like client-server, the processing load for the application was shared between code on the server and code installed on each client locally. In other words, an application had its own pre-compiled client program which served as its user interface and had to be separately installed on each user's personal computer. An upgrade to the server-side code of the application would typically also require an upgrade to the client-side code installed on each user workstation, adding to the support cost and decreasing productivity. Additionally, both the client and server components of the application were bound tightly to a particular computer architecture and operating system, which made porting them to other systems prohibitively expensive for all but the largest applications.
Later, in 1995, Netscape introduced the client-side scripting language called JavaScript, which allowed programmers to add dynamic elements to the user interface that ran on the client side. Essentially, instead of sending data to the server in order to generate an entire web page, the embedded scripts of the downloaded page can perform various tasks such as input validation or showing/hiding parts of the page.
"Progressive web apps", the term coined by designer Frances Berriman and Google Chrome engineer Alex Russell in 2015, refers to apps taking advantage of new features supported by modern browsers, which initially run inside a web browser tab but later can run completely offline and can be launched without entering the app URL in the browser.
Structure
[edit]Traditional PC applications are typically single-tiered, residing solely on the client machine. In contrast, web applications inherently facilitate a multi-tiered architecture. Though many variations are possible, the most common structure is the three-tiered application. In its most common form, the three tiers are called presentation, application and storage. The first tier, presentation, refers to a web browser itself. The second tier refers to any engine using dynamic web content technology (such as ASP, CGI, ColdFusion, Dart, JSP/Java, Node.js, PHP, Python or Ruby on Rails). The third tier refers to a database that stores data and determines the structure of a user interface. Essentially, when using the three-tiered system, the web browser sends requests to the engine, which then services them by making queries and updates against the database and generates a user interface.
The 3-tier solution may fall short when dealing with more complex applications, and may need to be replaced with the n-tiered approach; the greatest benefit of which is how business logic (which resides on the application tier) is broken down into a more fine-grained model.[4] Another benefit would be to add an integration tier, which separates the data tier and provides an easy-to-use interface to access the data.[4] For example, the client data would be accessed by calling a "list_clients()" function instead of making an SQL query directly against the client table on the database. This allows the underlying database to be replaced without making any change to the other tiers.[4]
There are some who view a web application as a two-tier architecture. This can be a "smart" client that performs all the work and queries a "dumb" server, or a "dumb" client that relies on a "smart" server.[4] The client would handle the presentation tier, the server would have the database (storage tier), and the business logic (application tier) would be on one of them or on both.[4] While this increases the scalability of the applications and separates the display and the database, it still does not allow for true specialization of layers, so most applications will outgrow this model.[4]
Security
[edit]This section needs additional citations for verification. (February 2018) |
Security breaches on these kinds of applications are a major concern because it can involve both enterprise information and private customer data. Protecting these assets is an important part of any web application, and there are some key operational areas that must be included in the development process.[5] This includes processes for authentication, authorization, asset handling, input, and logging and auditing. Building security into the applications from the beginning is sometimes more effective and less disruptive in the long run.
Development
[edit]Writing web applications is simplified with the use of web application frameworks. These frameworks facilitate rapid application development by allowing a development team to focus on the parts of their application which are unique to their goals without having to resolve common development issues such as user management.[6]
In addition, there is potential for the development of applications on Internet operating systems, although currently there are not many viable platforms that fit this model.[citation needed]
See also
[edit]References
[edit]- ^ "Web app | Definition, History, Development, Examples, Uses, & Facts | Britannica". www.britannica.com. Encyclopædia Britannica. Retrieved 4 November 2024.
- ^ "What is a Web App? - Web Application Explained - AWS". Amazon Web Services, Inc. Retrieved 4 November 2024.
- ^ "Web applications". DocForge. Archived from the original on 19 April 2015. Retrieved 9 November 2024.
- ^ a b c d e f Petersen, Jeremy (4 September 2008). "Benefits of using the n-tiered approach for web applications". Archived from the original on 1 December 2017. Retrieved 24 November 2017.
- ^ "Top Tips for Secure App Development". Dell.com. Archived from the original on 2012-05-22. Retrieved 2012-06-22.
- ^ Multiple (wiki). "Web application framework". Docforge. Archived from the original on 2020-06-20. Retrieved 2010-03-06.
External links
[edit]- HTML5 Draft recommendation, changes to HTML and related APIs to ease authoring of web-based applications.
- Web Applications Working Group at the World Wide Web Consortium (W3C)
- PWAs on Web.dev by Google Developers.
Web application
View on GrokipediaIntroduction
Definition
A web application, often abbreviated as web app, is application software that is stored on a remote server and delivered over the internet to a user's device, where it runs within a web browser interface via protocols such as HTTP or HTTPS.[7][8] This client-server model enables the delivery of dynamic, interactive content without the need for local installation or downloads on the user's device.[7] Unlike traditional desktop applications, web applications rely on the browser to handle execution, rendering, and user interactions.[9] Core attributes of web applications include their browser-based execution, which promotes cross-platform accessibility across various devices and operating systems through adherence to web standards such as HTML for content structure, CSS for presentation, and JavaScript for dynamic behavior.[10] The underlying HTTP protocol is inherently stateless, treating each request as independent unless explicit state management mechanisms, like sessions or cookies, are implemented to maintain user context across interactions. This design facilitates scalability and simplicity in deployment, as updates occur centrally on the server without user intervention.[8] Representative examples of web applications include email services like Gmail, which provide real-time messaging and attachment handling, and collaborative document editors such as Google Docs, enabling multiple users to edit content simultaneously in a browser.[7] Web applications emerged as an evolution from early static web pages, which primarily displayed fixed content, to more sophisticated interactive software that supports complex user experiences over the network.[8]Key Characteristics
Web applications exhibit platform independence by executing within any modern web browser, irrespective of the underlying operating system or hardware, due to adherence to universal web standards such as HTML, CSS, and JavaScript.[11] This interoperability is facilitated by the Web Platform Working Group's specifications, which ensure consistent rendering and functionality across diverse devices, from desktops to mobiles, without requiring platform-specific installations.[12] As a result, developers can target a broad audience with a single codebase, reducing fragmentation and promoting widespread accessibility.[13] A core trait of web applications is their support for dynamic interactivity, enabling real-time content updates without necessitating full page reloads, primarily through Asynchronous JavaScript and XML (AJAX) technology. AJAX allows client-side scripts to exchange data with servers asynchronously, refreshing only specific page elements to deliver seamless user experiences, such as auto-completing form fields or loading dynamic feeds.[14] This approach enhances responsiveness and reduces latency compared to traditional synchronous models, forming the foundation for modern interactive features in applications like collaborative editing tools.[15] Web applications are inherently designed for scalability, accommodating distributed access from numerous users by leveraging server-side resources to manage variable loads efficiently. Through horizontal scaling techniques, additional server instances can be provisioned dynamically to distribute traffic, ensuring reliable performance during peak usage without compromising availability.[16] Cloud platforms further amplify this by providing elastic infrastructure that automatically adjusts resources based on demand, allowing applications to handle global audiences effectively.[17] Accessibility is a fundamental characteristic, with web applications adhering to Web Content Accessibility Guidelines (WCAG) to ensure inclusive design for users with disabilities, including provisions for responsive layouts that adapt to various screen sizes and input methods. WCAG 2.2 emphasizes perceivable, operable, understandable, and robust content, mandating features like sufficient contrast, keyboard navigation, and reflowable layouts to support mobile and assistive technologies.[18] This compliance not only broadens user reach but also aligns with legal standards in many regions, promoting equitable digital experiences.[19] Web applications, often referred to as full stack apps when built with full stack development encompassing both frontend (user interface in the browser) and backend (server, database, logic) components, are accessible via any web browser on desktops or mobiles without requiring installation. In contrast, mobile apps are software applications designed specifically to run on mobile devices (smartphones, tablets), often native (platform-specific like iOS/Android), hybrid, or web-based (such as progressive web apps), typically installed from app stores and able to access device features like camera or GPS. Key differences include:[20]- Platform: Browser-based (full stack web applications) versus device-native or hybrid (mobile applications).
- Access: No installation needed (web applications) versus download and installation required (mobile applications).
- Performance: Mobile applications generally offer a faster, more responsive experience with offline capabilities and native hardware access.
- Development: Full stack web applications use web technologies (HTML/CSS/JS for frontend plus backend languages); mobile applications use native tools (Swift/Kotlin) or cross-platform frameworks (Flutter/React Native).
