Relative dating

Relative dating is a way of telling how long ago something happened compared to something else. It's like having a giant tape measure that lets us compare things that happened long ago with things that happened more recently. For example, if we found a fossil that was part of a tree, we could measure how long it had been since the tree died. That would tell us how old the fossil was. We could also use relative dating to measure how long ago two rocks were formed, or even how long ago a whole mountain formed. By measuring how long ago different events happened, we can figure out which things happened first and which happened later.