Work experience and internships will help you define what you do (and what you don't want to do), give you key skills, help you understand the general world of work and company culture, and enable you to make industry contacts.
This type of experience is valued so highly among employers because it means you are less of a risk. You have proven that you can do the job. It will also give you a solid reference, have provided you with training, and given you contacts which you may be able to transfer to your new employer.
It is key that you understand what you did during your work experience or internship and how to present it in a way which relates directly to the position for which you are applying. Think about the company and your contribution.
Thinking through these points and jotting down your answers will help you to pick out pertinent examples when putting together your covering letter or answering questions in an interview. It should also help you identify what you are good at, and think about what you enjoyed.
It is key to understand how what you did during your work experience relates to the position for which you are applying.
This exercise is not just valuable for formal work experience or internships, but for any part-time work as well. All experience is relevant if you know how to frame it in the right way. It's easy to overlook good work, management skills, and planning, but it is all part of the skill set that you are bringing with you.
If you have no work experience to speak of, read on for tips on dealing with a lack of experience.