时尚 (shíshàng): Fashionable; trendy. Describes what is currently popular in terms of clothing, accessories, or overall style.
流行 (liúxíng): Popular; in vogue. Refers to something that is widely accepted or followed by many people at a given time.
风格 (fēnggé): Style; manner; approach. Describes a distinctive way of doing things or expressing oneself.