The strategic importance of project management offices (PMOs) is not questionable therefore identifying the most specific and noticeable evaluation segments of PMOs leads to a better understanding of PMOs. As a starting point in our earlier publication along with the quest for the determination of a standardized, integrated, and comprehensive framework, we defined a PMO model summarizing grounding ideas of our research. This complex PMO model contains six building blocks that describe the complex role and status of PMO within the organization: the context (the environment of the PMO), the typology, the maturity, the internal processes of the PMO, the services, and the performance (the metrics of the PMO). This study concentrates on the services and the typology of a PMO, based on a deep dive in the different approaches of these two categories. We achieve this first by elaborating a clear description of them and secondly by analyzing the relationship between them and the other categories of the model. In our model, among the six categories 'typology' has the most direct connection to the organizational structure that a PMO serves. Following the analysis of state-of-the art and relevant publications about this category, we recognized that the typology has various definitions leading to diffuse meaning. This research clarifies this concept to give a proposal for the exact definition of typology. Publications on PMO 'services' do not emphasize the definition itself enough. Instead, they focus on the PMO responsibilities within an organization, the needs, and the objectives to achieve. Our research provides a collection of all the service elements, and different grouping concepts of them. In his study we suggest a unified list of PMO services, their descriptions, and a grouping approach in line with the aim of PMO operation.