A leader's job is to lead a team, by improving relationships, handling HR and project related tasks.

They are differentiated from lead designers, who are not leaders, but designers that lead the overall construction of a project, but not the entire team.

A lead designer's job is to lead the overall construction of a single project. They can become famous and seen as the creator of a line of product in the eyes of fans.

They are differentiated from leaders, who are not designers, but instead lead the entire team they are on, handling HR and project related tasks.

A design can refer to 2 things:

• The design of product, i.e. what it should do, how it should be constructed, etc. Usually comes in the form of a design document
• Hardware design, which is the final physical look of a piece of hardware

Unless hardware is specifically used, design will refer to the first of these 2, e.g. a description of how a product should work and be constructed.

Projects refer to a product that is being created, but is not yet finished.