At the end of each project is the realization of some specific goal or objective. It is not enough to assign a project to someone and say, „See what you can do with this.” Nebulous objectives will more than likely lead to a nebulous outcome. A specific objective increases the chances of leading to a specific outcome.

Objective
A desired outcome; something worth striving for; the overarching goal of a project;
the reason the project was initiated to begin with.

While there may be one major, clear, desired project objective, in pursuit of it there may be interim project objectives. The objectives of a project management team for a food processing company, for example, might be to improve the quality and taste of the company’s macaroni dish. Along the way, the team might conduct taste samples, survey consumers, research competitors, and so on.
Completion of each of these events can be regarded as an interim objective toward completion of the overall objective.
In many instances, project teams are charged with achieving a series of increasingly lofty objectives in pursuit of the final, ultimate objective. Indeed, in many cases, teams can only proceed in a stair step fashion to achieve the desired outcome. If they were to proceed in any other manner, they may not be able to develop the skills or insights along the way that will enable them to progress in a productive manner. And just as major league baseball teams start out in spring training by doing calisthenics, warm-up exercises, and reviewing the fundamentals of the game, such as base running, fielding, throwing, bunting and so on, so too are project teams charged with meeting a series of interim objectives and realizing a series of interim outcomes in order to hone their skills and capabilities.

The interim objectives and interim outcomes go by many names. Some people call them goals, some call them milestones, some call them phases, some call them tasks, some call them subtasks. Regardless of the terminology used, the intent is the same: to achieve a desired objective on time and on budget.

(10 Minute Guide to Project Management, by Jeff Davidson, MBA, CMC http://www.BreathingSpace.com)