A will gives either lots of information or not much depending on what the deceased wanted to do with their estate.
Administration simply gives a person the right to deal with the estate in whatever way they decide is best.
Below gives you a better idea of what is involved:-
Probate and letters of administration
Probate
If you are named in someone's will as an executor, you may have to apply for probate. This is a legal document which gives you the authority to share out the estate of the person who has died according to the instructions in the will. You do not always need probate to be able to deal with the estate.
If you have been named in a will as an executor, you don't have to act if you don't want to.
Letters of administration
In some circumstances, someone who wants to deal with the estate of someone who has died will have to apply for letters of administration, rather than probate. This person is called an administrator. You have to apply for letters of administration if:
there is no will
a will is not valid
there are no executors named in the will
the executors cannot or are unwilling to act.
There are strict rules about who can be an administrator. If there is a valid will, you can apply for letters of administration if:
the person who died left all of their estate to you in the will, and
the executors are not named, or cannot or are unwilling to act.
If there is no valid will, and you are the next-of-kin, you can apply to be an administrator in the following order of priority:
you are the married partner or civil partner of the person who has died
you are the child of the person who has died
you are the grandchild of the person who has died
you are the parent of the person who has died
you are the brother or sister of the person who has died
you are the nephew or niece of the person who has died
you are another relative of the person who has died.