Via PMI:
A project manager creates objectives; the project leader influences people and events to ensure those are met A project manager formulates plans; the project leader provides the vision and enthusiasm to achieve them A project manager monitors results; the project leader recognizes and initiates change to keep the project on track A project manager assigns activities; the project leader provides direction and motivation A project manager solves technical problems; the project leader encourages innovation A project manager puts the team together; the project leader fosters collaboration A project manager asks for feedback and information; the project leader explains how to make the information useful A project manager identifies stakeholders; the project leader analyzes and balances their expectations