Klienttipuolen

Klienttipuolen, meaning the client side, describes the portion of a software system that runs on the end user’s device rather than on a remote server. In web development, this includes the browser-executed code such as HTML, CSS, and JavaScript, responsible for presentation, user interaction, and initial data handling. The client side communicates with back-end services through APIs to fetch or submit data, while business logic and data persistence may reside on the server or, to some extent, on the client.

In contrast to the server side, which runs on servers controlled by the service provider, the client side executes in the user’s environment. This separation supports modular architectures, allowing developers to optimize responsiveness and reduce server load, but it also introduces concerns about security, trust, and data validation, since client-side code can be inspected and manipulated.

Common technologies include web front-end frameworks such as React, Angular, and Vue, along with vanilla HTML/CSS/JS. On mobile and desktop, client-side code may be implemented with native apps or cross-platform frameworks (e.g., React Native, Flutter, Electron). Client-side storage options include localStorage, sessionStorage, and IndexedDB, used for caching or offline support.

Key considerations for klien tipuolen include performance optimization, accessibility, cross-browser compatibility, and security. While the client side can enhance user experience through faster interactions and offline capabilities, critical security checks should be enforced on the server, and sensitive data should not be trusted to client-side validation alone.

Testing typically covers UI components, browser compatibility, and end-to-end flows, often complemented by server-side tests to verify API correctness.