Advisory implies a non-binding role focused on giving advice rather than making decisions. She joined the board in an advisory capacity to offer her expertise.
Pro Tip 2/3
Professional Context
Often used in formal, especially corporate or organizational, settings to describe groups providing expertise. He serves on the advisory council for environmental policies.
Pro Tip 3/3
Specialized Knowledge
Implies specialized knowledge or expertise the advisors share to guide others. The technical advisory group will assess the new software.