It is the celebration that is the origin of Halloween. Samhain was first observed by Celtic Pagans. Originating from an ancient Celtic spiritual tradition. It is usually celebrated from October 31 to November 1 Samhain marked the Celtic New Year, the end of summer, and the end of the harvest season. It also signalled the beginning of winter, which they associated with death.
Celebrants believe that the barriers between the physical world and the spirit world ("the veil") breaks down during Samhain, allowing more interaction between humans and denizens of the Otherworld.
In other words, it is the day of the dead. It is a time to reflect and honour ancestors who've left this world. As they can and most often times do, return to the earth.
Traditionally remember to leave an extra plate of your loved one's food at the dinner table. Create an altar space for them, with their photos, candles, a glass of water and various other offerings. And celebrate the end of the harvest with them.