Partir vs. salir

The Spanish words 'partir' and 'salir' both relate to leaving or departing, but they are used in different contexts.

Partir

'Partir' means 'to leave' or 'to depart', usually referring to a journey or trip. It is often used in more formal or written contexts.
Voy a partir mañana a las seis de la mañana.
(I will depart tomorrow at six in the morning.)
El tren partirá en unos minutos.
(The train will depart in a few minutes.)
Después de la reunión, ellos partirán hacia el norte.
(After the meeting, they will head north.)

Salir

'Salir' means 'to leave' or 'to go out', and is commonly used in everyday conversation to reference leaving a place, going out socially, or exiting.
Voy a salir con mis amigos esta noche.
(I am going out with my friends tonight.)
Salí de la oficina a las cinco.
(I left the office at five.)
¿A qué hora sale el autobús?
(What time does the bus leave?)

Summary

In summary, 'partir' is often used in more formal, written contexts or when referring to the start of a journey, while 'salir' is used for everyday situations involving leaving or going out.