Charities, education and non-profits should strive to make the greatest impact with their resources.
Focusing on outcomes and impact can motivate people, drive change and inform decision making frameworks. Knowing the outcomes you aim to achieve helps you prioritise strategy, align business planning and frame evaluations. When done right, outcomes affect the entire organisation, permeate all levels and demonstrate how all acivities fit together. There are many ways develop and implement outcomes and so the approach your organisation takes can be tailored to its culture and values.
Put simply, outcomes are changes that result from your organisation's activities. Good or bad (hopefully good). Intended or not. Directly attributable to your work or indirectly. Outcomes are the answer to the question 'so what?' Why do we exist? What have we been doing all these years? What is our purpose for the years ahead?
Ideally there would be a conscious link between your organisation's activities and the outcomes achieved - this is your Theory of Change. When looking ahead a theory of change could be considered to be a 'bet' - 'I bet if we do X then Y will happen.' You can strengthen your 'bet' through evidence, research and user engagement. Looking back a theory of change is an analysis - 'why when we did X did Y happen?' Again, evidence, research and user engagement will strengthen your analysis.
Consider: what would be different if your organisation did not exist? How do you know? Could you convince someone else of this?