Ok kiddo, let me explain what an Euclidean domain is.
An Euclidean domain is like a playground with blocks that can be arranged in a certain way. But, instead of using colorful blocks, we use numbers.
Let's say you have a number like 10 and you want to divide it by another number like 3. The division might not give a whole number answer, right? But, in an Euclidean domain, we can use a special rule to divide these numbers in a way that will always give a whole number answer or a remainder that is smaller than the divisor (the number we're dividing by).
This rule is like a game where we keep subtracting the divisor from the dividend (the number we're dividing) until we can't subtract anymore. The number of times we subtracted is the whole number answer we were looking for, and the remaining number is the remainder.
For example, if we want to divide 10 by 3, we can subtract 3 from 10 three times and get 1 left over. So, the whole number answer is 3 and the remainder is 1.
Now, what makes an Euclidean domain special is that we can always use this rule of subtraction to divide any two numbers in the domain, and get a whole number answer or a remainder that is smaller than the divisor.
That's why Euclidean domains are so useful in math and in real life! It's like having a playground with blocks that always fit together in a certain way, no matter what color or shape they are.