To "aim" is to direct, as in a missile, blow, weapon, word or act. This aim could be toward or against something or someone. The word also means having a purpose or an endeavor. To "aim" is to set out an intention. The broad aim of a course or lesson should express the intended goal to be reached by the end.
An "objective," in the sense of "aims and objectives," is a goal or purpose, as of a mission or assignment. An "objective" is the goal you want the student to achieve by the end of the course or lesson. Objectives are smaller, bite-sized goals that should be SMART---Specific, Measurable, Achievable, Realistic and Timely. Therefore, each objective should be a small step toward the broader aim.
A simple educational example of aims and objectives for a lesson plan might read:
Aim: To create a complete individual Photostory using Photostory 3 software by the end of today's session.
Objectives:
1. To talk about what Photostory does
2. To import pictures into Photostory
3. To create a "title" image
4. To rotate an image
5. To delete an image
6. To add titles and captions
7. To add music to Photostory
8. To save Photostory for playback
Notice how the aim is broad and the objectives are smaller chunks that enable the learner to get to the final goal.
As you write aims and objectives, remember the SMART rule. Ask yourself if the aim and all the objectives are Specific, Measurable, Achievable, Realistic and Timely. For example, if you wrote an aim for an English lesson that stated, "All students will achieve an understanding of Hamlet's character," it would not meet the SMART criteria. This aim is vague, does not suggest a timescale and includes no clear way of measuring understanding. It is also unrealistic to expect all students to have achieved this goal. A SMART version of this aim might be, "All students will have engaged with the text of Shakespeare's Hamlet and will have written down answers to three questions about Hamlet's character by the end of the session." The objectives would break down this broad goal further to ensure that all students will have a measurable achievement by the end of the session.