Change management involves preparing for, managing, and reinforcing organizational changes. It requires the involvement of project teams, senior leaders, managers, and employees. There are typically three phases: preparing for change by defining strategies and teams, managing change through implementation plans, and reinforcing change by collecting feedback and celebrating successes. The ADKAR model outlines five aspects for successful change: awareness, desire, knowledge, ability, and reinforcement. Change management connects activities like communication and training to business results through achieving ADKAR.