What have you already done? This is your opportunity to demonstrate your competence with the technologies and methods proposed in your project. Present preliminary results that support the hypothesis and feasibility of your proposed project. Use figures or charts to illustrate important points of your preliminary work. Include a critical evaluation of the results. Show reviewers you are aware of alternate interpretations and know how to think through problems. This will build reviewers' confidence in your ability to think critically and handle the challenges of future research. If you have relevant manuscripts that have been submitted for publication, include these in an appendix (if allowable, according to sponsor guidelines). Be sure to differentiate between results reported by you and those reported by others.
If you are applying for a supplemental or continuation grant, this is where you present your progress report on the already funded research. Consult sponsor guidelines on what should be included in the progress report.