they share same meaning. but laowai(老外） originally has offensive meaning... people r used to call foreigners laowai instead of waiguoren nowadays. so laowai is more casual, waiguoren is more formal.

They are exactly same.

I think laowai老外 is used in nord china I never use this word 外国人 is the right expression

both are the same meaning, but 老外is often used in spoken compared with '外国人'.

They have the same meaning.But 外国人 is more formal.They just like "ping-pong" and "table tennis" in English.