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 are found in very harsh conditions such as in the volcanic vents or at the bottom of the sea. They. are often called  extremophiles . They can easily survive in such extreme environment as sea vents releasing sulfideârich gases, hot springs, or boiling mud around volcanoes.