A directory is the generic term given to a website that allows you to list basic details about your club. You may set up a page in a directory in the hope that potential new members will find you. Whilst directories do not generally attract a lot of members they take little effort to set up, are mostly free to subscribe to and usually do not require much maintenance as the basic details about the club (such as its location) do not alter often.
However, it is important to keep a list of the directories that you subscribe to in case some contact details, such as contact telephone number or email address, do change.
Common directories are set up by local councils and regional areas (municipalities, cities and or towns). Others are sometimes set up that are based around sports in general or your own particular sport.
One really effective way to see the popular directories in your area is to search for local sporting clubs using a search engine to see what other local clubs are listed on. They do not have to be in the same sport. You may need to search for the names of a few clubs in your sport to see what type of specific sports-based directories they are subscribed to.