Hi wkm1925,
ToList calls List<T>(IEnumerable<T>) constructor to create a List<T>, while ToArrary uses an internal class Buffer<T> to grow the array.
If the source collection (IEnumerable<T>) implements the ICollection interface, the two methods use similar code logic to copy the data.
Otherwise, ToList will creates the List<T> dynamically.
While ToArray copies the element one by one into a new array. If the array if full, the method doubles the array size to hold the data.
Finally the method returns another array based on the source collection's size.
Unless you simply need an array to meet other constraints you should use ToList. In the majority of scenarios ToArray will allocate more memory than ToList.
Both use arrays for storage, but ToList has a more flexible constraint. It needs the array to be at least as large as the number of elements in the collection. If the array is larger, that is not a problem. However ToArray needs the array to be sized exactly to the number of elements.
Refer below link for more details.
https://stackoverflow.com/questions/1105990/is-it-better-to-call-tolist-or-toarray-in-linq-queries
https://dotnettutorials.net/lesson/tolist-and-toarray-methods-linq/
