Employees are leaders, designers, artists, programmers, support, lawyers or accountants. People who are occupied with directly adding value to the company. Employees will spend their day sitting at a computer to work.

The term differentiates itself from staff, who are occupied with keeping operations running smoothly so the employees can work, e.g. cleaners, cooks, maintenance, etc.

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

A task is a job that usually has a card in the right side of the UI. It can be a contract to create some software, the alpha phase of the player's own project, a lawsuit, etc.

Work items and tasks can be used interchangeably in most cases, but work items refer to the actual UI element, so tasks is more general.