Goals in Warchest are what you hope to raise; they represent a campaign’s fundraising ambition. Goals can be based on a blend of current projections and a subjective, desired result. Goal setting is optional.
Projections are what campaign’s are expecting to raise. Projections are based on historic fundraising data and current fundraising projections - i.e. future fundraising projections for events, call time, online, etc.
Projections act like future budgeted expenses in the budget tab. The "difference" on the Finance Plan is calculated as actual raised minus projected raise.