Buffer is a tool that allows users to schedule social media posts to multiple accounts. The document provides step-by-step instructions on how to sign up for Buffer and connect social media accounts like Twitter and Facebook. It then explains how to schedule posts and choose the dates and times for Buffer to automatically share content to linked accounts. Users can upload images and links to share on their networks. With Buffer, social media users can pre-plan their posting strategy and share content to multiple platforms with just one click.