They are a set of outcomes (ideally) that the organisation promises to achieve. It is accountable for managing for these outcomes. In a more global theory of change, there may be a whole set of intermediate outcomes, and only a few will be chosen as objectives for that given program/ strategy.

But in practice objectives tend to be located at varying places in a theory of change model. Sometimes they are activities, sometimes they are foundational activities, sometimes milestones, sometimes intermediate outcomes and sometimes high level outcomes! Objectives are not defined by their position in a hierarchy of change, they are defined more by the fact that they are a promise to deliver. So it all depends where the program is sitting to where the objectives will sit. They are a relative term, not an absolute term.

I’d love to hear what you think of my take on this

Some dictionary definitions that relate to organsational use of the term (selected from wickipedia):

• Objective (military), the achievement of a final set of actions within a given military operation …
• Objective - aim: the goal intended to be attained (and which is believed to be attainable); “the sole object of her trip was to see her children” 
• goal or objective is a projected state of affairs that a person or a system plans or intends to achieve-a personal or organizational desired …
• The Objective is a 2008 science fiction horror film directed by award-winning filmmaker Daniel Myrick, who also directed The Blair Witch Project. It stars Jonas Ball, Matt Anderson, and Michael C. Williams. …
• A military objective is a clearly defined desired result in a given campaign, major operation, battle, or engagement set by the senior command for their formations and units to achieve. …
  are the broadest statements of what the organization chooses to accomplish. (300.02.1)
• In a proposal, the objectives are statements of anticipated outcomes. Objectives are stated in measurable terms and tell the grantor who will do what, when, how much, and how it will be measured. …
• objective - A statement of intention or description of a goal. As with any objective, it should be specific, measurable, achievable, realistic and time-bound …
• objective - A concrete statement describing what the project is trying to achieve. The objective should be written at a low level, so that it can be evaluated at the conclusion of a project to see whether it was achieved or not.