When writing your Will, it is important to name an executor. The executor is responsible for managing the administration of your estate and obtaining a grant of probate, if required. Once your executor has liquidated or transferred your assets they are then responsible for paying everything out to the beneficiaries.
It is important to nominate at least one executor, and it is often recommended that you name a replacement executor just in case your original executor is unable to act for whatever reason. You need to discuss this with your named executors first, as the duties involved can be onerous and time consuming.
You can choose anyone to act as your Executor as long as they are over 18.