A collaborative real-time editor is a type of collaborative software or a web application which enables real-time collaborative editing, simultaneous editing, or live editing of the same digital document, computer file or cloud-stored data – such as an online spreadsheet, word processing document, database or presentation – at the same time by different users on different computers or mobile devices, with the automatic and nearly instantaneous merging of their edits.
Real-time collaborative editing can occur online in web applications such as Microsoft Office on the web (formerly Office Online) – which supports online (web-based) simultaneous editing (which Microsoft refers to as "Co-Authoring") of Word documents, Excel spreadsheets, PowerPoint and other Microsoft Office documents stored on Office.com, OneDrive or SharePoint cloud storage – or Google Docs and other G Suite productivity (office suite) apps – for online collaborative editing of word processing and other documents stored in Google Drive. Real-time collaborative editing can also occur in a hybrid manner, such as with Power Sheet BI for Excel, in offline, web-based, and online collaborative editing in desktop software as well as web-based and mobile apps, which can be synchronized automatically with instant access to version history.
Unlike asynchronous (non-real-time, delayed, or offline) collaborative editing, such as occurs with revision control systems like Git or Subversion, real-time editing performs automatic, periodic, often nearly instantaneous synchronization of edits of all online users as they edit the document on their own device. This is designed to avoid or minimize edit conflicts. In asynchronous collaborative editing, each user must typically manually submit (publish, push or commit), update (refresh, pull, download, or sync) and (if any edit conflicts occur) merge their edits.
Due to the delayed nature of asynchronous collaborative editing, multiple users can end up editing the same line, word, row, element, data, row or field resulting in edit conflicts which require manual edit merging or overwriting, requiring the user to choose which edits to use or (depending on the system and setup) automatically overwriting their edits or other people's edits, with or without a warning.