"Ser" and "Estar" both translate into 'to be' however they are used in different situations.Generally, the difference can be understood as Nature (Ser) vs State (Estar). Ser is used in order to describe what someone or something is at its very nature. Meanwhile Estar is used in order to describe what the state of someone or something is in a certain moment.However, separate to this general distinction it is important to remember Ser is always used for Time and Date.As the general difference can be hard to remember, there are two acronyms to make this easier to understand.For Ser, the acronym 'DOCTOR' can be used: Date, Occupation, Characteristic, Time, Origin, Relationship.And for Estar, the acronym 'PLACE' can be used: Position, Location, Action, Condition, Emotion.