Here, the class parameter for the command \documentclass specifies gyongyos.info file to use for the document. It is recommended.
For each class, LaTeX provides a class file; the user arranges to use it via a \ documentclass command at the top of the document. So a document starting.
There's a category in the TeX Catalogue: Alternative Document Classes (web . the output from my pdflatex run, because that is what the standalone class does.