What is the difference between ser and estar?

the two verbs ser and estar, in Castilian Spanish both mean "to be" in English. The confusion for non native speakers comes when trying to identify within which contexts you are supposed to use which verb, luckily there are rules, and they just require a little bit of memorisation. broadly speaking, "estar" is used with relation to motion/movement, states of being, and emotions. For example: estar lejos - to be faraway, or estar feliz - to be happy. On the other hand, "ser" is often said to be used with much more concrete expressions, things that don't change, such as physical appearance, relationships, or job titles. Like, to say "es mi padre", he is my dad, since that relationship is not a temporary state it wouldn't be correct to use estar in place of ser, or "ser profesor" - to be a teacher, since it's a profession, or job title, you would use estar. One thing I know that trips people up and they think is a mistake is when people use "estar muerto" -to be dead/to have died, because in English this is a permanent state, but in Spanish it comes under the class of a state of being, and that's why you use estar with that type of expression.