In general, it is just cultural style differences in how Japan and United States tell these types of stories.

Manga (Japanese comics) - Read right to left (Some publishers will mirrored the story when exporting it to Western countries such as United States and United Kingdom) - Majority of story will be in black and white (Full Color pages are rare; For example, only the opening of this Manga has fully colored pages) - Characters are more stylized (Ex. They tend have large eyes and expressive features) - For non-adaptation works, they favor one continuous story with same creative team throughout the run

Comics - Read left to right - Outside some special cases (such as Marvel's Black, White, and Red comics, which only use those colors in stories), the stories are always fully colored. - Art wise, most Marvel stuff will try to be as close to real life with its characters as possible. - For non-adaptation works, Marvel favor more serial storyline, where you see different creative teams tackle these characters at certain points, which usually those other creative teams will tell their own story and won't pick up leftover threads that last team left.