What is the relationship between the record date and ex-dividend date in international trading markets?

Ex-dividend date is like a dividing line to establish the right to receive dividend

Record date is the date on which who will receive the dividend is determined.

Ex-dividend date is always prior to record date. If a transaction is completed before ex-dividend date, then the new owner of the security is entitled to receive dividend on record date. If transaction is completed on or after ex-dividend date, then the seller is entitled to receive dividend on record date.