difference bw box and border box

.alligator-box {
  box-sizing: border-box;
  width: 125px;
  height: 125px;
  border-width: 10px;
  padding: 40px;
}

.alligator-box {
  box-sizing: content-box;
  width: 125px;
  height: 125px;
  border-width: 10px;
  padding: 40px;
}