Dear friend, Tags are the keywords which search engines looks first. When a user searches about any thing in the web the search engines match it with the tags given to a resources. So better tags means better chances of appearing the resources in search results.
Adding tags wisely brings you more traffic. But you will not get any points by adding tags. Instead it allows visitors to find your articles easily. So try to add tags while posting articles. See this to know How to use TagsNijin Forum Editor SPK
Tags are probable words that are commonly used by users for searching a topic. Each topics will have a particular words which are commonly used by the users. So it should used by the writer to get more attraction to the users while searching in the search engine. It is a skill and one can achieve it by keen study of the topic