An executor/executrix is the personal representative of an estate.  They are the person in charge of taking control of assets, paying debts, and distributing assets to beneficiaries per the terms and conditions of the will.  You can choose anyone to be the executor/executrix of your will, but it is a good idea to choose someone who is both competent and trustworthy.  The person you choose to be executor/executrix should be outlined in your will.  Someone you appoint to be the executor/executrix of your will has the right to refuse, so you should have a backup executor/executrix in place just in case.