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

Both 'ser' and 'estar' translate as 'to be' in English, so it's a little confusing to know which one to use. The most basic rule is that 'ser' is used for permanent states such as a characteristic or someone's occupation, whilst 'estar' is used for temporary states, such as the location of something or emotions. For example, 'soy una persona feliz' means 'I am a happy person'. So, the 1st person singular of 'ser' ('soy') is used because it is a permanent characteristic. However, to say 'I am happy' in a particular moment, so as a temporary emotion, we have to use 'estoy', from the verb 'estar' ('estoy feliz')

A great way to remember the main uses of each verb is by using the following acronyms: DOCTOR (for 'ser') - Date, Occupation, Characteristic, Time, Origin, Relation... and PLACE (for 'estar') - Position, Location, Action, Condition, Emotion.