What problem does HBAR solve?

Could you elaborate on the specific problem that HBAR addresses? I'm interested in understanding the challenges it aims to overcome in the realm of cryptocurrency and finance. What gap does it fill in the current market landscape? How does it differ from other solutions that might already exist? I'm particularly keen on grasping its unique value proposition and how it can potentially revolutionize the industry. Could you provide a concise yet comprehensive explanation of its core functionality and the problem it solves?