Manna is the bread directly given from Heaven by God to the Israelites during their exodus in the desert.
Manna was given to the Israelites as food during the time when they were living in the desert for 40 years. It arrived with dew during the night, and melted in the sun. It would rain down every day but the sixth day, the day before Shabbat, the Sabbath, Preperation Day. They were instructed to gather twice as much on the sixth day to eat during Shabbat. If anybody kept the manna past the day it was gathered, it would breed worms and rot, except for the Sabbath.
It was white like corriander, and like hoarfrost in size, looking similar to bdellium. Israelites would grind it up and make it into cakes.
According to the Mishnah, Manna was created on the sixth day of creation.
The Manna stopped coming when they had come out of their Exodus, and the last remaining Manna is sealed in a jar, kept inside of the Ark of the Covenant.
According to the Talmud, Manna tasted like honey to children, bread to adults, and oil to old people. It would appear closer to the people more faithful to God, and further away from those less faithful.