When certain Anime/Manga is brought to America & edited in some way. This might be to conform with different guidelines regarding children's programming or to combine episodes, or several other reasons.
American dub anime use censorship to protect their young audiences from racial insults, graphic sexual act, nudity, excessive exposure of skin, religious references, and many more. Some anime were also localized by editing out items and phrases that are only understandable to the Japanese. Sometimes, excessive censorships can hurt the company and the franchise such as One Piece, Yugioh, Pokemon, and many more.
Note: List reasons in alphabetical order. Give a brief example with a link to the volume or episode page.