Uncensored smut manga often features explicit and graphic sexual content. The art style can vary, but it usually aims to be visually stimulating for mature audiences.
Straight smut manga often features explicit and adult-oriented content, focusing on romantic or sexual encounters without much emphasis on complex storylines.
Well, smut manga typically features a lot of sexual imagery and scenarios. Regular manga, on the other hand, can be about anything from superheroes to school life and doesn't focus mainly on sexual themes. The main difference is the emphasis on sexuality in smut manga.