Executors, those people who will carry out the wishes in your Will. You can name up to 4 people as Executors and it is generally a good idea to have at least 2, so you have effectively a reserve in place in case one of the Executors cannot act at that time.
Beneficiaries, those people or organisations, charities etc who will receive your bequests.
Note: a Beneficiary can also be an Executor.
You can nominate Guardians for minor children, if appropriate.
You can note your Funeral wishes.