The technologies involved in communication tend to be complex. You certainly don't need to understand them for your ICT course. However, there are aspects of digital communications that you needs to be aware of. These relate primarily to the two types of network and the ways of connecting to the internet.
Archaeans include inhabitants of some of the most extreme environments on the planet. Some live near rift vents in the deep sea at temperatures well over 100 degrees Centigrade. Others live in hot springs (such as the ones pictured above), or in extremely alkaline or acid waters.
Archaebacteria --Prokaryotic, unicellular, nutrition by absorption (heterotrophic). This group of bacteria-like organisms live in harsh (high temperature, salinity, etc.) environments similar to that of ancient earth (hence the name).They cell wall structure is different than that of typical bacteria.. Eubacteria --Prokaryotic, unicellular, nutrition mainly by absorption (heterotrophic) with some photo-or chemosynthesis (autotrophic) all single celled organisms with no membrane surrounding the genetic material (Bacteria, Blue-green algae) and circular DNA.