From the word itself, Magic is all about spells and the way you mange
them. Imagine, you and your buddy are playing. You cast a spell, but
your friend casts something too. Then you argue that you were first, but
your friend says otherwise. Then you begin to
slap each others face. Then there's a brawl and you could hear people
shouting and cheering. Do you want that to happen? Wouldn't that be so
chaotic? haha That's why Wizards created a system of taking turns and
casting spells one at a time.
Hence, we came to know about the terms "Priority and
Stack." They are all weaved together as they are inter related..