Samhain is celebrated by Celts at the end of summer. It marks the end of summer and the beginning of the new year. It is/was a time to wrap up summer activities and get ready for winter. Samhain is celebrated by the entire group (versus Imbolog which is celebrated in family groups), out of doors, and lasts the entire night.
It is a time for inner reflection and a time to square yourself away. This festival has been adopted by other western cultures and is generally called Halloween. There is minimal connection between Samhain and Halloween these days. Halloween is somewhat frivolous while Samhain is serious and not to be taken lightly…though all involved enjoy themselves. Most importantly, Halloween has come to rest on the premise of a devil or evil. Celts do/did not believe in devils and/or evil spirits. Thus, Samhain is at once more and less serious than Halloween. For Celts, it is/was the time of the “in-between”. That is, a change from the time of light to the time of dark. It was/is thought that spirits could move easily from one realm to the other. These were/are not evil spirits but ancestors returning to visit loved ones.