Boxing is the process of converting a value type to a reference type, while unboxing is the process of extracting a value type from a reference type.
Boxing and unboxing can introduce overhead in terms of memory pressure, CPU cost, and type safety risks.
Using generics instead of non-generic collections, avoiding object parameters for value types, and being cautious with interfaces can help minimize boxing/unboxing issues.
In a loop of 10 million iterations, boxing can make the code 10 times slower compared to without boxing.