Annual Fund / Close the Gap Fundraising Model

We are a K-12 school and we are aiming to switch to an annual fund/close the gap fundraising model. We had some questions regarding how schools who are using a close the gap model handle their budgets and whether the funds raised are used to offset budgeted line items or if donations are used for the bottom line. Also, it would be helpful to know how those gifts are coded within RE. If anyone has any advice, or would like to share how their schools handle the annual fund/close the gap donations and budget, it would be super appreciated. Thank you.