Pac-Man is the maze game that turned arcades from shooting galleries into something everyone played. Namco released it in 1980, designed by Toru Iwatani, and the rules have not needed changing since: clear every dot in the maze while four ghosts hunt you, and use the four power pellets in the corners to turn the tables for a few seconds.
This page runs a faithful browser remake — the same maze, the same 240 dots, the same ghost personalities — with keyboard controls and no download. It is the Pac-Man most people mean when they search for it, distinct from Google's 2010 anniversary doodle (which has a Google-logo maze and is on our Google Games hub).
It is a browser remake of the 1980 Namco arcade game with the original maze, dot layout, ghost behaviour and scoring. The arcade's speed tables and the famous level-256 'kill screen' are approximations in most remakes, including this one.
Google's version is the 30th-anniversary doodle from May 2010: a maze shaped like the Google logo, playable by searching 'pacman'. This page is the classic maze. Both are free; the Google one is listed on our Google Games hub.
Yes. It is a keyboard game that runs in the browser with nothing to install, and it is light enough for any Chromebook. Whether the site loads on a school network is up to that network's filter.