Bento, originally meaning "something convenient, handy, smooth". After being introduced to Japan, the word dangdang (当て字) was used as an expression for "便道", "辨道", "辨当", etc. The word "dangdang" was later introduced to China as an expression of "convenience" ("方便"). The word "Bento" was later imported back into China from the Japanese word "bentou" (phonetic: bentou). It has been simplified to Bento, which is customarily referred to as "boxed rice" in most parts of the mainland, i.e., boxed meals. In Taiwan, it is generally called Bento, and is usually used for lunch, take-out, and work meals. There is a slight difference in usage between "bento" and "boxed lunch", with the term "boxed lunch" being more oriented towards simple and rough meals, such as the term "Japanese bento", which is seldom used. The term "Japanese bento" is rarely referred to as "Japanese boxed lunch".
Takeout is simply when you order food at home and someone else delivers it to your house.
Bento is like the Japanese anime where a mom makes lunch for her kids at home, packs it in a lunchbox, and brings it to school.