Dylan,
Rocks are 90 Day priorities that are written "SMART" (Specific, Measurable, Attainable, Realistic, Timebound). Rocks are created at the Quarterly Pulsing meeting and a single person owns each Rock. They are due at the following Quarterly Pulsing meeting.
Issues are any topics that need to be resolved by the team. An issue could be a problem, obstacle, idea or opportunity; anything that needs to be set up and knocked down using I.D.S. (Identify, Discuss, Solve).
Often times the solution to an Issue is a to-do's (7 day action items) created in your weekly Level 10 Meeting. Sometimes an Issue is solved with a Rocks (90-day priorities) in your Quarterly Pulsing meeting.
Feel free to message me directly if you still need help.
This video might also help: