A torrent tracker is a piece of software which tracks Torrents. It will record the number of leechers, number of seeders, how large the torrent is, what files are contained in the torrent, and how many times the torrent has been downloaded. You can think of it like a statistics tracker for torrents.
The unit of the Maya writing system is the glyphic cartouche, which is equivalent to the words and sentences of a modern language. Maya cartouches included at least three or four glyphs and as many as fifty. Each cartouche contained various glyphs, as well as prefixes and suffixes. There is no Maya alphabet.
Mayan writing was called hieroglyphics or hieroglyphs by early European explorers of the 18th and 19th centuries who did not understand it but found its general appearance reminiscent of Egyptian hieroglyphs, to which the Mayan writing system is not at all related.