Understanding the Differences: Custom GPTs, Bots, Artifacts, and Agents

Hello, I need help with some terms and am seeking guidance from someone with more experience. What is the difference between custom GPTs (OpenAI), bots (Poe.com), artifacts (Claude), and agents in general?

Also, does what we do with Pickaxe fall under the category of custom GPTs or bots? Thank you.

CustomGPTs bots and Pickaxes are all pretty similar.

Pickaxe studio is a product that allows you to sell one or more Pickaxes.

Artifacts or agents essentially take on multiple steps in a segmented fashion to do more elaborate things than is readily possible with Pickaxe at this time.

Thank you for your response.