What is the 4% rule ETF?

Could you please elaborate on what exactly the "4% rule ETF" refers to? I'm interested in understanding its underlying principles, potential benefits, and any risks associated with it. Additionally, how does it fit into a broader investment strategy? Is it suitable for all investors, or are there specific circumstances where it's more appropriate? Finally, could you provide some examples of ETFs that adhere to the 4% rule? Thank you for your assistance in clarifying this concept.