A contribution includes an addition to your field’s overall knowledge. It is the main idea of your paper and the main purpose of your research. It answers questions like: What are you researching?
Your answer to the awkward question is “the contribution”. We have produced a something worth knowing from our research, and it speaks with, and to, what is already known about our particular topic. The contribution is our offering to the scholarly conversation.
A thesis proposal is a document that outlines the thesis topic, defines the issues that the thesis will address, and explains why the topic warrants further research. It should identify a problem and provide a proposed solution to that problem.
A research proposal is a concise and coherent summary of your proposed research. It sets out the central issues or questions that you intend to address. It outlines the general area of study within which your research falls, referring to the current state of knowledge and any recent debates on the topic.