Minimal Solution
A minimal SOP will consist of prime implicants.
A minimal SOP equation will have all of the essential prime implicants on the map. By definition, these cover a minterm that may not be covered by some other prime implicant.
The minimal SOP equation may or may not include non-essential prime implicants. It will include non-essential prime implicants if there are ‘1’s remaining that have not been covered by an essential prime implicant.