A web application, commonly referred to as a web app, is a type of software application that runs on web servers and is accessed through a web browser over the internet. Unlike traditional desktop applications, which are installed locally on a user’s computer, web applications are hosted on remote servers and can be accessed from any device with an internet connection.

Key characteristics of web applications include:

1. Accessibility: Web applications are accessible from any device with a web browser and an internet connection, including desktop computers, laptops, tablets, and smartphones. This makes them highly versatile and convenient for users who need to access the application on the go.

2. Platform Independence: Since web applications run within a web browser, they are platform-independent and can be accessed from different operating systems, such as Windows, macOS, Linux, iOS, and Android. This eliminates the need for developers to create separate versions of the application for different platforms.

3. Centralized Deployment: Web applications are centrally deployed on web servers, which means that updates and changes can be implemented centrally without requiring users to download or install any updates. This ensures that all users have access to the latest version of the application at all times.

4. Scalability: Web applications can easily scale to accommodate a growing number of users or increased workload by adding more server resources or utilizing cloud-based infrastructure. This allows the application to handle fluctuations in traffic and user demand without sacrificing performance or reliability.

5. Cross-Device Compatibility: Web applications are designed to be responsive and adapt to different screen sizes and device types, ensuring a consistent user experience across desktop and mobile devices. This is achieved through responsive design techniques and frameworks that optimize the layout and functionality of the application for different devices.

6. Integration with Web Services: Web applications can leverage the capabilities of web services and APIs (Application Programming Interfaces) to integrate with external systems, databases, and third-party services. This enables functionality such as user authentication, data synchronization, and real-time updates from external sources.

7. Security: Security is a critical consideration for web applications, and developers must implement measures to protect against common security threats, such as cross-site scripting (XSS), SQL injection, and data breaches. This may include using encryption, authentication mechanisms, and security protocols to safeguard user data and ensure the integrity of the application.