Subsequence
In mathmatics, a subsequence is a sequence that can be derived from another sequence by deleting some or no elememts without changing the order of the remaining elememts.
What is Sequence?
In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed. Serial arrangement in which things follow in logical order or a recurrent pattern.
Substring
Substring can be derived from the string by deleting anoter substring. The substring is a refinement of the subsequence.
