Use the same evidence standard, source hierarchy, analysis sequence and output structure every time you investigate a market or topic.
A normal prompt lives in the conversation where you give it. You can certainly save prompts and reuse them, but the burden is still largely on you to bring the process back into the chat.
A Skill is designed as a reusable package. Its name and description help ChatGPT recognize when it is relevant, its core instructions define the workflow, and supporting resources can provide the examples, standards, schemas, templates or deterministic scripts that the job genuinely needs.
The important shift is consistency. Instead of hoping you remember the six things that make the task work properly, you package those six things into the Skill and make the workflow part of the tool.

