# Introduction SIGNIUS Harmony is a local desktop component for eIDAS compliant remote signing with Qualified Electronic Signatures. Besides SIGNIUS Harmony, you'll also need an application that allows you to place and submit your digital signature to a document or file. ### Overview This documentation describes how to: * Install SINIUS HARMONY Desktop app on your computer. * Logon-on and Log-off * Sign PDF, MS-Word, PAdES (PDF in SECUREDOC), XAdES (XML in SECUREDOC) documents * Request support --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.signius.eu/manuals/harmony-desktop-en/introduction.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.