Klientprogram

Klientprogram is a software component that runs on a user's device and communicates with a server to obtain resources or services over a network. It presents an interface to the user, collects input, and processes data received from the server. In the traditional client–server model, the client initiates requests and the server responds with the requested data or actions. Klientprograms are contrasted with server programs, which reside on servers and provide resources, data, or processing.

Structure often includes a user interface, application logic, and data access or caching layers. Depending on the design, a klientprogram may be a thin client with minimal processing or a thick (rich) client that performs substantial work offline or with local storage. Communication typically uses standard network protocols such as HTTP/HTTPS, FTP, SMTP, or WebSocket, and data is commonly exchanged in formats like JSON or XML, or binary protocols in specialized cases. Modern klientprograms frequently rely on API-based servers (REST or GraphQL) and may authenticate with tokens or cookies.

Examples include web browsers, email clients, desktop or mobile applications that connect to cloud services, database clients, and remote-desktop clients. In many cases, web applications blur the line, as the browser acts as a klientprogram that communicates with back-end services.

Security considerations for klientprograms include secure transport (TLS), credential storage, input validation, and proper session management. Interoperability and performance are influenced by platform, framework, and network conditions. Overall, the klientprogram is the user-facing component in a client–server ecosystem that enables interactive access to services and resources.