M&E are two distinct elements which work to compliment each other.
Monitoring is an ongoing activity during the life of a project that aims to provide stakeholders and rights holders with information regarding the performance of any ongoing activities (Estrella & Gaventa, 1998; Onyango, 2018).
Specifically, it helps to determine whether the stakeholders and rights holders need to make any meaningful changes in the activities being undertaken, so that it can be as efficient as possible (Estrella et al., 2000; Kananura et al., 2017). It uses the systematic, continuous collection of data on specified indicators to provide insight into whether a project is on track, and if any of its strategies or activities need to be changed so that it can be successful (Shah et al., 2006; World Bank, 2011). It is an internal project activity, and essential part of day to day management (Casley & Kumar, 1987).
Evaluation is an assessment, as systematic and objective as possible, of an ongoing or completed project, its design, implementation, and results. The aim is to determine the relevance and fulfilment of objectives, developmental efficiency, effectiveness, impact, and sustainability. The main purposes of evaluation are to isolate errors and take corrective action, as well as to highlight the successful mechanisms for current and future activities (Jackson & Kassam, 1998). Therefore, evaluation measures achievement, as well as positive or negative and intended or unintended effects (Kariuki, 2014). An evaluation should provide information that is credible and useful, enabling the incorporation of lessons learned into the decision-making process of everyone involved.
Monitoring and evaluation are interactive and mutually supportive processes. M&E provides stakeholders with better means for learning from past experience, improving service delivery, planning and allocating resources, and demonstrating results as part of accountability to rights holders and key stakeholders.
It is important that both of these phases (monitoring and evaluation) are conducted, so that accurate information can be obtained and used to analyze the system in relation to particular objectives. This is especially critical given the dynamic nature of socio-ecological systems, which may inevitably change project goals or strategies over time.