The global warming we are witnessing has led to huge risks for companies to consider but also significant opportunities to exploit. The clean energy transition is happening now. Companies of all sizes have begun to take meaningful action to reduce their enterprise-wide emissions and establish more sustainable business processes. To become more competitive, they have to act to not be left behind in the low-carbon future. This guide offers a dictionary of most common terms and describes key concepts that companies need to understand to make the decisions and choices that work for their unique needs and sustainability/decarbonization goals.