What does record date and ex-date mean?

EX - This is the date, on or after which if someone buys a share of the company he or she will not be eligible to get the benefit of corporate action like dividend payout. This is the date on which the stock starts being traded without any benefit of corporate actions to shareholders.

This is the date the company checks the record, if your name is registered in the name of shareholders, then only you will be entitled to get the benefit of dividends or other corporate actions like rights issues, bonus shares or stock splits.

Unusually, ex-date and record-date both are kept on the same date, hence if you purchase shares of a company on the records date you would not be entitled to get the benefit of such corporate actions.