Easy-to-use Canvas boards let you visually organize any project in Jira.
Project issues can be organized as cards - simply drag them to transition, change priorities, reschedule, or assign.
You can easily combine one or more different projects into a board to view issues (as long as you have access to each of the projects).
A typical use is by a user who does not have permission to create project boards in Jira, they can instead create their own Canvas Board to keep track of issues across multiple projects.