A sports coat may be more than one color and compliments rather than matches a pair of pants; blazers are a solid color and compliment rather than match a pair of pants, and a suit jacket matches a pair of pants. Today's sport jackets are dressy jackets, looser cut than a business suit jacket, with or without pocket flaps worked in various fabrics and colors. They may or may not have elbow patches. I hope this helps.

Oxford Fine Menswear