Bonjour can be mean Hello and Good morning

안녕 (informal)
ㅎㅇ (하이) (Slang & Texting, informal / casual)
안녕하세요 (formal / polite)
안녕하십니까 (honorific / very polite)

안녕 is informal or casual used to the same age(friend), someone younger than you, the children, lover
(low formality / low politeness)

안녕하세요 is 세 is honorific + 요 is informal (but still) polite used to strangers(someone you don't know), olders, seniors, teacher, boss, everyone
(low formality / high politeness)

안녕하십니까 is honorific or very polite used to olders, elders, seniors, boss, army, officers, everyone.
(high formality / high politeness)
(Bonjour/Hello/Hi for Greeting)

Literally: 좋은 아침 but "안녕" Or 잘 잤어? 잘 잤니?(Meaning : Did you have a good night's sleep? or Did you sleep well?) (informal / casual)

Literally: 좋은 아침이에요 / 입니다 but "안녕하세요" Or 잘 잤어요? 요 is informal but polite Or 안녕히 주무셨어요? more formal(polite)(Meaning : Did you have a good night's sleep? or Did you sleep well?) (formal / polite)

굿모닝 - Konglish "good morning"
(Good morning)