WebApplicationFirewalls

A web application is software that runs over the internet and is accessed through a web browser or other HTTP client. It provides interactive functionality and dynamic content, unlike static websites. It may store user data, interact with servers, and integrate external services.

Web applications typically consist of frontend components that execute in the user's browser and backend components that run on servers. They connect to databases and external APIs to retrieve and persist data. The client and server communicate over HTTP or HTTPS, often using session cookies, tokens, or API keys to manage authentication and state.

Common architectures divide concerns into presentation, application logic, and data storage. Frontend can be traditional multi-page or modern single-page applications, while the backend may be monolithic or organized as microservices. Progressive web apps extend capabilities to work offline and install like native apps.

Technologies include markup, styling, and scripting on the client side, and server-side languages and frameworks on the back end. Communication often uses REST or GraphQL APIs; data is stored in relational or NoSQL databases. Security and accessibility are key considerations.

Development involves planning, coding, testing, and deployment, followed by monitoring and maintenance. Authentication and authorization are essential; common practices include OAuth and OpenID Connect. Common security risks include XSS, CSRF, and SQL injection.

Deployment typically runs on cloud platforms or on-premises, often via containers and orchestration tools. Performance optimizations include caching, content delivery networks, and scalable infrastructure. Web applications cover a wide range of uses, from e-commerce and productivity tools to collaboration platforms.