What is a linear protocol?

Excuse me, could you please clarify what exactly is meant by the term "linear protocol" in the context of cryptocurrency and finance? Is it a specific type of agreement or set of rules that governs transactions or interactions in a sequential or ordered manner? And if so, how does it differ from other protocols that may operate in a more decentralized or parallel fashion? I'm curious to understand the unique features and applications of a linear protocol in this field.