Tags are used on My Community Directory in conjunction with Categories to clarify what your service offers. Whilst the Category of a listing determines the main focus of the service (Mental Health, Sports Club, Youth Information etc.) a tag will allow you to further specify features of your service (Anxiety, Kids Sport, Youth Health Centres etc).

Tags are also used as part of the search algorithm and using them correctly is a key way to make it easier for people to find your listing.
For example, a listing for a Sports Club that specialises in Cricket will be more likely to appear in a search for 'Cricket' if the listing has the 'cricket' Tag. 
On the other hand, if the same Sports Club used the Tag 'Dental Health' it is unlikely to appear in searches for cricket clubs.

The more accurate Tags you use for your listing - the more relevant searches your listing will appear in.