Too Long; Didn't ReadThe `concat` method on arrays is used to take two arrays and concatenate them into one. It takes as many arrays as you like - so you can concate many arrays at once. The method creates a shallow copy of the array it's applied to, with the addition of any other arrays added to the end. Nested arrays are concatenated in the same order that the outer array is removed, meaning the outer elements are removed. The basic premise is that the arrays we used in `Concat` maintain the same reference in memory.