Nowadays, modern Geoinformation Systems (CIS) are considered being an element of a much wider concept, namely Spatial Data Infrastructure (SDI). The paper starts with description of objectives and a vision of SDI and the role of GTS within the SDI. Then it describes technological requirements for modern GIS and SDI implementation, followed by articulation of benefits of deployment of GIS within a SDI context. Next, the paper analyses the GI data sets, which are required to achieve the benefits of the SDI and GIS deployment and draws attention to the importance of cadastral data within SDI. The final part of the paper discusses the significance of cadastre as a foundation of modern GIS and SDI and its essential rote in achieving the most critical quantifiable benefits of GIS and SDI.