Holiday と vacation は同じ意味ですか？

Once again Obon is upon us which means quiet local train rides in Tokyo, congested highways, and packed malls. Are you enjoying the holidays? or Are you enjoying your vacation? Is there any difference?

I suppose it depends on where you are from. In American English a holiday is usually a special day of remembrance or celebration like Independence day or Thanksgiving. A vacation is usually longer, a few days or a few weeks. In British English a holiday means vacation.

There are also banking holidays or national holidays, like Respect for the Aged Day or Culture Day.

Anyway, I hope you are enjoying your Obon holidays. I will be taking a 3-day vacation starting tomorrow. Why do we celebrate Obon anyways? Can someone please explain? (Actually read Nick's blogs about relative clauses first and then try to explain it using relative clauses)

congested- 密集｛みっしゅう｝した、混雑した
drive on a heavily congested road- ひどく混んでいる道路｛どうろ｝を運転｛うんてん｝する
My nose is congested- 鼻がぐずぐずしている

packed- 混んだ、人でいっぱいの、すし詰めの、満員｛まんいん｝の、満席｛まんせき｝の、ぎゅうぎゅうで
packed train- 満員電車｛まんいんでんしゃ｝、満員列車
The trains which leave or arrive every few minutes are packed like sardines. :
数分おきに発着する電車は、すし詰め状態である。