The word Ogham (pronounced OH-yam) has been used to refer to:

A group of twenty trees, sacred to the Druids, that give names to the letters of the Ogham alphabet.

An alphabet of twenty-five characters used for inscriptions on magickal tools in Celtic Ireland & Britain.

An alphabet of twenty characters used for divination and hand-signing in Celtic paganism.

A calendar of thirteen months named for each of the sacred trees.

Below you will find a modern-day interpretation of the Celtic tree calendar. Besides using trees as a way of telling the seasons, the druids used them for many other things. These are called Oghams. Linked to this calendar, you will find much more information on each individual ogham or tree, including the meanings of each during divination.

Oghams were often used by the Celts of olde as a tool of divination, yet they were also used as an alphabet to inscribe many things. First, you must make your own set & inscribe each letter on something made of wood. (Some use stone or tile.) Then place them in a bag for storage. Now when you are ready to use them in divination, find a quiet, peaceful place to sit. Meditate briefly on the question that you want to ask. Then draw out 3 of the pieces and see what the correspondences are. This should help you determine the answer to the question. You may also use them to inscribe your name on your magickal tools or to write in your Grimoire or Book of Shadow, just to be on the safe side & so no one can understand your writings. Oghams are also often used on amulets and talismans.

Don't forget to look for the meaning of each.
It is under each name link.