CL-20, HMX, and LLM-105 are high-energy explosives that are utilized in military applications due to their ability to produce a large amount of energy from a smaller mass compared to conventional explosives. Their chemical structures allow for greater stability and sensitivity, making them efficient for use in various munitions and weapon systems. This understanding is crucial in the context of military technology and defense strategies, which are often discussed in the realm of national security and geopolitics in UPSC Prelims syllabus.