A dividend is the distribution of profits and retained earnings a company usually pays out yearly to its shareholders.
If you hold an open position on an CFD index which distribute dividends before the ex-date then you are entitled to receive the dividend amount either as a credit or debit.
Dividend date, also known as reinvestment date, is an investment term that includes the time dividends are paid in company stocks.
The amount of dividend it is incorporated onto the swap value in points in your metatrader5 account.
You can see the overall swap amount in points under symbols specifications in your MT5.