What is the difference between planning and grooming in software development?

Planning: Takes place at the beginning of the iteration (sprint). The team selects tasks from the product backlog based on their priority and estimates. The scope of work for the sprint is determined, and tasks are distributed among team members. The goal is to create a clear work plan for the iteration, define objectives, and agree on what will be ready by the end of the sprint.

Backlog Refinement / Grooming: A continuous, ongoing process (which can take up to 10% of the team's time) that occurs throughout the iteration. It focuses on elaborating and clarifying product backlog items. User stories are discussed, details are added, readiness criteria are clarified, and complexity is assessed. The goal is to ensure that backlog items are sufficiently understood, detailed, and estimated for subsequent planning. Grooming makes planning more efficient, as the team is already familiar with the tasks.