"Interesting" refers to something that captures attention, arouses curiosity, or is engaging and captivating. On the other hand, "uninteresting" refers to something lacking these qualities, being boring, dull, or not worthy of attention or interest.
When describing a person, an "uninteresting" individual may be someone who lacks charisma or fails to hold the attention of others. In a broader sense, an "uninteresting" book or movie may lack plot twists, engaging characters, or a compelling storyline.