ShareX is a free, open-source screen capture and sharing tool that allows users to easily capture screenshots, record videos, and share them online. It offers a wide range of advanced features such as customizable hotkeys, image and text annotations, automatic file naming, and various upload options including FTP, Google Drive, and Dropbox. Additionally, ShareX also supports OCR (optical character recognition) and QR code scanning, making it a versatile and efficient tool for both personal and professional use.