Hi good day, please I still don't get the concept of combinations with repetition. just like the example given in the pdf file I downloaded

Hey Roman, Thank you for your question! Let's consider the 3-topping pizza example given in the pdf. The task is to choose 3 toppings out of 6 available. Let's consider the various types of combinatorics one can apply to this problem. If you need to choose 3 different toppings and don't mind their arrangement (cheese can come before onions, and vice versa), then we are dealing with combinations without repetition. If you need to choose 3 toppings, with repetitions allowed, and still don't mind their arrangement (cheese, cheese and onions would be the same as cheese, onions, and cheese), then we are dealing with combinations with repetition. If you need to choose 3 different toppings and the order matters to you (cheese, bacon and onions is not the same as bacon, onions, and cheese), then we are dealing with variations without repetition. If you need to choose 3 toppings, with repetitions allowed, but the order still matters to you, then we are dealing with variations with repetition. Hope this would help you follow the instructions in the pdf more easily! :) Kind regards, 365 Hristina

So let me get this clear. For combination the order doesn't really matter whether with or without repetition right? but for variation order of arrangement matters. I need to understand the whole concept clearly because in the exercise given in the pdf I downloaded I was confused with when to apply the variation or combination.