"Skill" is the ability to do something well. "Skills" are names of specific things someone knows how to do. For example: (Skill) He has skill in public speaking; he gives a very good speech. She is very skillful with a camera. She is a highly skilled photographer. (Skills) Her skills include computer programming and singing. Playing golf is not one of his skills.

skill - singular, 1, Skills - Plural, 2 or more