Monitoring and evaluation are interrelated practices but they have different methodologies and scopes. Monitoring can highlight that we are not on track toward the desired results while an evaluation can be conducted to understand "why" we are not going in the right direction.
The evaluation is an objective and systematic appreciation of an ongoing or finished project, program or policy in terms of its design, implementation and achieved results. The main goal of evaluation is to analyse the relevance of a program/project and its contribution to global objectives, efficiency, effectiveness, impact and sustainability.
