Serving as a mentor for a fourth-grader, I have had a year both challenging and rewarding.
A participle is a verbal ending in -ing (present) or -ed, -en, -d, -t, -n, or -ne (past) that functions as an adjective by modifying nouns and pronouns. A participle phrase begins with a participle.
In the sentence, the participle phrase modifies the noun 'year'.
