Estimating Cost vs. Establishing the Project's Budget

What is the difference between Estimation of Project Cost (PP SP 1.4) and Establishing Project Budget (PP SP 2.1)?

Project Planning (PP) Specific Practice (SP) 1.4 addresses estimating the effort and cost for the project’s work products and tasks based on specified estimation rationale, models, and/or historical data. SP 2.1 takes this information for the individual work products and tasks, along with the major milestones identified in the project’s defined life cycle, any scheduling assumptions and constraints, and task predecessor/successor relationships to construct the project’s schedule and overall budget. Simply put, SP 1.4 concerns individual items in the project and SP 2.1 concerns the project as a whole.