It is important for students to have knowledge about the basic characteristicsof technological systems, because they differ in crucial respects comparedto single technological artefacts. Moreover, many technological systems have a farreachingimpact on society and the environment, while at the same time they aresocially shaped and controlled by human beings. In the literature such systemsare often called socio-technical systems. The aim of this chapter is to investigatethe key characteristics of technological systems in time and space, in order toinform teaching of technological systems. The specific characteristics of technologicalsystems include them being: socio-technical with both societal and technicalcomponents; developed by system builders and managed by professional organizations;with a spatial scope ranging from local/city-wide, regional, national to globalnetworks; dependent on control features including feedback loops as crucial mechanismsfor making the systems stable. These technological systems also evolve—and sometimes devolve—in distinct phases and in particular societal, economic andgeographical contexts, which may have repercussions when they are transferred.Furthermore, the systems are dependent on each other which over time and spaceleads to an entanglement of systems. Technological systems, finally, have a hugeimpact on the environment, which is why students will need to critically considerthe human dependence on systems. This chapter introduces a number of systemsconcepts that might also be fruitfully used as educational concepts in teaching abouttechnological systems. This way students can learn to generalize knowledge of technologicalsystems, so that they can take on, understand and critique different kindsof systems, even ones that have not been designed yet.