Inter- (between)
Inter-
Between or among.
Our school hosted the inter-school science fair in Pune.
International
Between many countries.
The international flight to Dubai left from Kochi.
Interval
A short break between two parts.
We bought samosas during the interval of the film.
Remember: Inter- = between (inter-school: between schools). Intra- = within (intra-school: inside one school). One letter changes the meaning.