“Manga” is the Japanese word for basically “comic”. In the English speaking communities it generally refers to Japanese comics where the primary difference is that the panels are generally read right to left whereas the text inside (if it’s been translated) is usually read in our typical left to right.

There’s more cultural differences largely stemming from how in the West (or at least my experience here in America) comics were often considered for kids or niche nerd communities, whereas in Japan it’s been more acceptable for a wider audience to read them for a longer time, but webcomics have been making the medium more accessible and thereby more acceptable for wider audiences so that stigma has been slowly being diminished.