Differentiate between Select() and SelectMany() method in LINQ.

The Select() and the SelectMany() are both used to produce result values form the sources of data. However, the difference is the result set. On the one hand, the select clause produces one result value for every source value, and the result value is the collection that contains the same number of elements from the query. On the other hand, the SelectMany() produces a single result that keeps a concatenated collection from the query.