What's the main difference between a "spear" and a "lance?"

Native speaker’s answer
Rebecca
From what I understand, a "lance" is a lightweight "spear." So it's still a spear, just lighter! But it's more likely you'll hear and use the word "spear" than "lance." Some people may not know what "lance" is or think that it's a name! Ex: I need a spear for my Halloween costume. Ex: Out of all the spears, I prefer to use lances.