An algorithmic skeleton is like the bones of a body. Just like our bones give us structure and help us move, algorithmic skeletons are pre-defined ways of writing code that give structure to a computer program and help it do certain tasks.
For example, if you want to write a program that sorts a list of numbers, you could use an algorithmic skeleton called "quicksort". This skeleton gives you a basic framework for how to go about sorting the numbers, so you don't have to come up with all the little details yourself. It's like having a recipe for a cake - you don't have to figure out all the ingredients and how to mix them, because the recipe tells you what to do.
Different algorithmic skeletons are useful for different tasks. Some are good for sorting data, some are good for searching through data, and some are good for creating graphics or animations. By using these predefined structures, programmers can save time and avoid making mistakes when they write their code.