Google Sheets is a spreadsheet application included as part of the free, web-based Google Docs Editors suite offered by Google. Google Sheets is available as a web application; a mobile app for: Android, iOS, and as a desktop application on Google's ChromeOS. The app is compatible with Microsoft Excel file formats. The app allows users to create and edit files online while collaborating with other users in real-time. Edits are tracked by which user made them, along with a revision history. Where an editor is making changes is highlighted with an editor-specific color and cursor. A permissions system regulates what users can do. Updates have introduced features that use machine learning, including "Explore", which offers answers based on natural language questions in the spreadsheet. Sheets is one of the services provided by Google that also includes Google Docs, Google Slides, Google Drawings, Google Forms, Google Sites and Google Keep.