If the deceased left a Will, their named executor will usually need to apply for a Grant of Probate. This is a court-sealed document which confirms that the executor has the legal authority to deal with the deceased person's assets. This is called 'administering the estate'.
Through a Grant of Probate, executors are able to act immediately though it is wise for them to wait until the grant has been issued. The executor uses the grant to show that they have the right to access funds, sort out finances and collect in the assets such as the closure of accounts, sale / transfer of shareholdings and investments, and sell any property the deceased may have owned. The executor can then distribute the deceased person's estate in accordance with the terms set out in the Will.
More than one executor?
All of the executors named in the will may apply to the Probate Registry for a Grant of Probate but it is not necessary that they all do so.
Sometimes, the presence of several executors, and/or impracticalities from a geographical position, just increases the paperwork and time spent administering the estate without any obvious benefit to the estate.