What do the null aware operators, specifically the null coalescing operator and the null aware access operator, actually do, and how do they let you write more concise code when working with nullable values?

The null aware access operator, written as a question mark followed by a dot, safely calls a method or accesses a property on a potentially nullable value, automatically returning null instead of throwing an error if that value actually happens to be null at that point, while the null coalescing operator, written as two consecutive question marks, provides a convenient fallback default value to use specifically in the case where the expression immediately preceding it does turn out to be null, and combining both of these operators together lets you write noticeably more concise code compared to writing out the equivalent explicit if null check statements every single time.

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