Generally copying someone else's work to pass off as your own is considered plagiarism. You are correct that it would additionally be infringing.
Yes, unless you have permission from the copyright holder or an exemption in the law.
copyright infringement
Copying a movie is copyright infringement, punishable by fines of $750-$30,000.
Unauthorized copying, altering, distributing, or performing/displaying a work is copyright infringement.
Copying, altering, distributing, or performing/displaying works that are not your own is copyright infringement.
Altering, copying, distributing, or in certain cases displaying a work without permission of the copyright holder is an infringement of his or her copyright.
Copying, altering, distributing, or performing/displaying the file without permission from the copyright holder or an exemption in the law would be considered infringement.
Assuming the graphics and animations are not in the public domain, and that your webpage would not qualify for a "fair use" exemption yes copying the material would be an infringement of copyright.
'Copyright infringement' means the unauthorised copying, downloading, etc of copyright material - songs, photos, movies, texts etc. It is illegal and people caught doing it may be punished by the law.
The legal term (and concept) is "copyright infringement". This is more accurate, as "violation" is more properly a term for criminal activities, not civil actions, and copyright law is Civil Law (though, unfortunately, there now also exists certain Criminal Laws for certain copyright infringement situations). Specifically, copyright infringement is the copying (in whole or in part) of a copyrighted work without the express consent of the copyright owner of that work. There are specific exceptions to where certain amounts of copying are legal (most prominently, but not exclusively, the "Fair Use" doctrine).
Copyright infringement in general is copying, altering, or distributing protected material without the permission of the copyright holder. If you have a software license to put a program on one computer and you put it on two, you have infringed the copyright. More details can be found in the End User Licensing Agreement (EULA) of the program.
Even if you buy a recording of a song, you've only paid for that one instance of it; copying it (say, to share with a friend) is copyright infringement.