1. Deployment Options: Freshservice offers both cloud-based and on-premise deployment options, providing flexibility for organizations depending on their IT infrastructure requirements. On the other hand, Zammad is primarily a self-hosted open-source software, which gives users more control over their data and system customization.

2. Automation Capabilities: Freshservice provides advanced automation features such as smart suggestions, automated ticket assignment, and workflow automations to streamline IT service management processes. Meanwhile, Zammad focuses on a robust Trigger system that allows users to automate actions based on predefined conditions, providing powerful customization options.

3. Ticketing System Customization: Freshservice offers a user-friendly interface with customizable ticket fields, forms, and templates, allowing organizations to tailor their ticketing system according to their specific needs. In contrast, Zammad provides extensive customization options through objects like triggers, macros, and dynamic fields, empowering users to create a personalized ticketing environment.

4. Integration Options: Freshservice comes with a wide range of integrations with popular third-party tools such as Slack, Jira, and Salesforce, enhancing its functionality and usability within existing IT ecosystems. In comparison, Zammad offers integrations with various communication channels like email, social media, and web forms, enabling unified ticket creation and management across multiple platforms.

5. Knowledge Base Functionality: Freshservice includes a robust knowledge base feature with AI-powered smart suggestions, article versioning, and content categorization to help users easily access relevant information and solutions. On the other hand, Zammad's knowledge base focuses on organizing articles with categories, tags, and attachments, providing a structured repository for efficient knowledge sharing within the organization.

6. Reporting and Analytics: Freshservice offers comprehensive reporting capabilities with customizable dashboards, real-time insights, and SLA compliance tracking to monitor IT service performance and identify areas for improvement. In contrast, Zammad provides basic reporting features like ticket metrics, agent performance tracking, and customer satisfaction surveys, allowing users to assess key service metrics and make data-driven decisions.

In Summary, Freshservice and Zammad differ in deployment options, automation capabilities, ticketing system customization, integration options, knowledge base functionality, and reporting and analytics features.