[Slack](https://slack.com/) is a cloud-based, team-communication app designed to allow groups of all sizes to work together and converse in a centralized and collaborative platform. The tools primary goal is to simplify and streamline conversations (ie. replace internal email threads) and while it shares similarities with several other chat services (AOL Instant Messager, Google Hangouts), Slack's basic efficiency features, robust integrations marketplace, extensive personalization options, and forever-free plan have made it one of the go-to communication tools for both business and personal users.
Each individual Slack group is called a Workspace - the overarching company or team behind the group. Within each workspace (users can join multiple different groups), conversations are broken down into direct messages and channels (which can be public to the team or private for select users), and users can seamlessly share files, images, and links across both. Members of a workspace can also integrate a wide range of [external apps](https://slack.com/apps) to centralize information and streamline processes - essentially operating a connected app from within Slack.
Slack launched in the summer of 2013 and currently has over 12.5 million daily active users.
The app is available and accessible in a variety of different forms:
- Web-based - operates effectively across all modern browsers
- Desktop - updated applications for Windows, OS, and Linux
- Mobile - free to download on both iOS and Android