this isn’t really gonna be helpful after the fact, but .htaccess files can hold a lot of settings relating to your Apache webserver (that wouldn’t ordinarily be available unless you had root access to your machine and apache’s configuration file — aptly named httpd.conf).
the most common use for it is to restrict access to a file or a folder by triggering a username/password dialog box when the specific url is accessed. other times, people use it to map friendly URLs against the querystrings that are understood by dynamic pages such as those generated by WordPress.
i guess the other lesson here is that in the *nix world, similar names have related functions. apache’s webserver name is httpd, for example, and htaccess is the way we configure httpd’s method for accessing a given directory :)