Principles are ways of successfully dealing with reality to get what you want out of life.
Ray Dalio, one of the world’s most successful investors and entrepreneurs, cites principles as his key to success.
Avoid fixating on irrelevant details. You have to determine what's important and what's unimportant at each level. For example, imagine you are designing a house. First you need to start with the big picture: Your house will sit on a plot of land, and you have to think through where the water comes from, how the house gets hooked up to the power grid, and so on. Then you need to decide how many rooms it will have, where the doors will go, where you need windows, and so on. When designing the plan, you need to think about all of these things and connect them, but that doesn't mean that you actually need to go out and pick the hinges for the door yourself. You just need to know that you'll need a door with hinges and how it fits into the bigger picture of the house.