Pipelines and stages in YellowRocket refer to the system for organizing and tracking the progress of leads or deals through various stages of the sales process. Users can create customized pipelines tailored to their specific sales workflows, defining different stages that correspond to different milestones or actions within the sales journey. This feature enables users to efficiently manage and monitor the status of leads or deals, ensuring they are effectively nurtured and moved towards conversion. Additionally, pipelines and stages provide valuable insights into the overall sales performance and help teams prioritize and focus on the most promising opportunities.