Opportunities are partnership opportunities: any endeavour in which the individuals involved are seeking partners. Opportunities include initiatives and ideas.
Initiatives are well-defined opportunities with clear objectives, requirements and timelines. These may include research projects, co-op and internship opportunities, requests for information and so forth.
Ideas are opportunities in the early stages of development that may not yet have a clear direction. These may be presented as a problem faced, a potential solution to an existing challenge or a high-level project concept.