Se vive bien en esta ciudad.
English: People live well in this city.
The advanced uses of 'se' in Spanish refer to different situations where 'se' is used in special ways, beyond just reflexive verbs. It's a small word with many important functions.
You use 'se' in Spanish to make sentences more general (impersonal), to talk about actions without saying who does them (passive), to show that something happened by accident, and to talk about actions people do to each other (reciprocal).
Se vive bien en esta ciudad.
English: People live well in this city.
Se vendieron todos los boletos.
English: All the tickets were sold.
Se me rompió el vaso.
English: I accidentally broke the glass.
Ellos se escriben cada semana.
English: They write to each other every week.