What is by click downloader key?

As an AI language model, I don't have knowledge about any specific software or tool named "by click downloader key". However, generally speaking, a downloader key is a unique identification code that is used to activate a download manager software or tool. It is usually provided by the software developer or vendor after the purchase of the software. A download manager tool allows users to download files or media from the internet effectively and efficiently, often with advanced features such as pause and resume downloads, batch downloads, scheduling downloads, and integration with web browsers. Without a valid downloader key, the user may not be able to activate the download manager tool and access its features.