“Eshaku” is greeting bow and the most easy bow. It is often used in daily life amongst friends, family, colleagues, etc. It has various meanings including“good morning”,“good afternoon”,“thank you” and“excuse me”.
30 degrees: Polite bow(keirei)
When you greet someone of a higher rank, for example your boss, client, someone you feel that is superior to you. Keirei is more polite than Eshaku.
This bow is commonly used in business situations such as greeting(potential) business partners or customers, or to show respect to someone of higher status.
45 degrees: Respect bow(Saikeirei)
“Sai” means“the most”. Saikeirei is the most formal of these three bows and is used in serious circumstances. It can be used to show respect to someone of very high status or to show a strong sense of apology.