What is mintlayer?

So, can you tell me, what exactly is Mintlayer? Is it a new type of cryptocurrency or a blockchain platform? How does it differ from other existing blockchain solutions in the market? And what kind of applications can it potentially support? I'm intrigued by the idea of layer 2 scaling solutions and how they can help enhance the performance of blockchain networks, so I'm particularly interested in how Mintlayer addresses these challenges. Can you elaborate on its unique features and advantages?