SharePoint 2013 provides an on-premise and cloud platform with improved performance, scalability, and social features. Key capabilities include simplified global navigation, deferred social and upgrade processes, distributed caching, and improved search performance through query rules and result-driven sources. Collaboration is enhanced through features like My Sites, communities, newsfeeds, following, tasks, and file sync. The platform also offers improved SEO, cross-site navigation, and device-specific experiences.