What is ETN Bitcoin?

Excuse me, could you please clarify what exactly is meant by "ETN Bitcoin"? I'm familiar with Bitcoin as a decentralized digital currency, but the acronym "ETN" isn't immediately clear to me. Does it stand for a specific technology, platform, or service related to Bitcoin? Is it a type of token or exchange-traded note tied to the value of Bitcoin? And how does it differ from traditional Bitcoin transactions or investments? I'm eager to learn more about this concept and how it fits into the broader cryptocurrency landscape.