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.
Eubacteria. The archaebacteria grow in unusual environments such as salt brines, hot springs and in the ocean depths. They are a group of most primitive prokaryotes which are believed to have evolved immediately after the evolution of the first life. They are of three types:-methanogens, Halophiles and thermoacidophilies.