What is the difference between the verbs 'ser' and 'estar'

'Ser' and 'estar' refer to the verb 'to be'. However, in Spanish the verb 'to be' can be used in different ways depending on the context. For example 'estar' refers to a an emotional state that can vary with time eg. 'estoy enamorado' (I am in love) or 'estoy de buen humor' (I am in a good mood) , while 'ser' would be used when you are talking about something permanent that is a characteristic unlikely to change eg. 'Soy de Madrid' (I am from Madrid) or 'Eres muy gracioso' (You are very funny)