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.
Methanogens have been found in several extreme environments on Earth-buried under kilometres of ice in Greenland and living in hot, dry desert soil. They can reproduce at temperatures of 15 to 100 degrees Celsius. They are known to be the most common archaebacteria in deep subterranean habitats.