Explain your organization and what it does, and why it matters. Use your elevator pitch as a starting point.
This should be how you would explain what your organization does if you were describing it to someone on the street. Feel free to include a short history of the organization, and whatever research has been done around the impact of the organization. Make sure to include any information that would be needed to know what the organization is about.
Remember to explain why your organization exists first. If you cannot explain why, take some time to figure it out. Without knowing why your organization exists you will be throwing money, time, and effort away without reason. The why behind your organization will inform everything else going forward in this plan.
Keep it short. You will have space later to describe what you do.