Definitions
Definitions of the following terms vary across schools, colleges and institutions. For clarity and consistency, the University of Wisconsin School of Medicine and Public Health Office of Community Service Programs uses the definitions below:
Service-Learning
The long-term aim of service learning is social change and social justice through the service provided by students as well as through their lifelong commitment to community engagement. 
Service-learning is a structured learning experience that combines community service with preparation and reflection. Students engaged in service-learning provide community service in response to community-identified concerns and learn about the context in which service is provided, the connection between their service and their academic coursework, and their roles as citizens and professionals.
(This is the definition used by the LCME, with the following citation: Definition from Cashman and Seifer MD. "Service-Learning: An Integral Part of Undergraduate Public Health." American Journal of Preventive Medicine; 35(3):273-278 (2008).)
In achieving a balance between service and learning, authentic service-learning experiences have several common characteristics. They:
- Are positive, meaningful and real to the participants
- Involve cooperative rather than competitive experiences and thus promote skills associated with teamwork and community involvement and citizenship
- Address complex problems in complex settings rather than simplified problems in isolation
- Include a reflection component that helps students synthesize their theoretical and practical learning
- Offer opportunities to engage in problem-solving by requiring participants to gain knowledge of the specific context of their service-learning activity and community challenges, rather than only to draw upon generalized or abstract knowledge such as might come from a textbook; as a result, service-learning offers powerful opportunities to acquire the habits of critical thinking, particularly, the ability to identify the most important questions or issues within a real-world situation
- Promote deeper learning because the results are immediate and uncontrived; there are no "right answers" in the back of the book
- Are reciprocal in nature, benefiting both the community and the service providers by combining a service experience with a learning experience
From Cashman and Seifer MD. "Service-Learning: An Integral Part of Undergraduate Public Health." American Journal of Preventive Medicine; 35(3):273-278 (2008).
Community and Civic Engagement 
Engagement is defined as the collaboration between institutions of higher education and their larger communities (local, regional/state, national, global) for the mutually beneficial exchange of knowledge and resources in a context of partnership and reciprocity.
(Definition from Carnegie Foundation’s elective classification for Community Engagement, copyright 2007 The Carnegie Foundation for the Advancement of Teaching.)
Community Service
Volunteering with a community agency, department or non-profit, in order to contribute to the common good.
Community/Campus Partnerships
Developing and nurturing partnerships between communities and higher educational institutions as a strategy for social change. Partnerships balance power, resources and decision-making, and are designed to benefit both partners.
(Definition from Community-Campus Partnerships for Health, copyright 2008)