Probability Difference Between Permutation, Combinations and Variations

Hi - I can follow the formulas, but I'm having a hard time defining the concept event on my own - which I think is most imp bc I need to be able to recognize it to apply it. Is this Right? Permutations - set number of elements and positions - How many possible distinct ways can you arrange them? Variations -   you have a set number of positions just like permutations - however you have multiple options for each options         But this can include the ability for repetition of the elements in each position or not include that Combinations - this is another animal bc the main difference is it is just like a variation in theory EXCEPT you have to pick a set number of elements for the available positions and your total number of possible elements will always be greater than the available positions you use.   Is this right? Anyone tell me, even a student in their own words?  Is this conceptually correct?