The Paschal Moon is the first Full Moon on or after March 21 and is used to determine the date of Easter. In some years, the Paschal Moon is the Worm Moon; in others, it's the Pink Moon (Full Moon in April). The dates for the Paschal Moon range from March 21 to April 18.
The Full Moon has been integral to tracking the change of months and seasons since ancient times.
Today, we use many of these ancient month names as Full Moon names, and many of them come from the Colonial Americans adopting Native American names into their calendars.
Although the most commonly used Full Moon names are English interpretations of Native American names, some are also Celtic, Anglo-Saxon, medieval English, and Neo-Pagan.