This review will examine the academic literature over which role the internet has in the evolution of extremism and terrorism since its advent. It will compare two different approaches. The first claims that the internet is a major factor that facilitates ideas and narratives, which can lead to the rise of extremism and terrorism. The second, which in its turn contradicts this approach, argues that prior the advent of the internet extremists and terrorists where more successful into achieving their goals. For that reason, the review will be split into 3 sections. The first section will be examining some needed key definitions of what constitutes terrorism and extremism. Afterwards the essay will shift its approach towards the main debate of whether the internet has a causal link with extremism and terrorism or not. Therefore Sect. 2 brings forth the ways, in which the internet has helped terrorism to advance its goals. Moving on to the third section, this piece of work will discuss the approach in which the internet does not assist extremist narratives but, in the contrary helps the advancement of better research around it and its prevention. Lastly, the review will sum up over the literature that has been discussed and conclude that there is always space for future research.