A specific keyword is something that contains many adjectives or words that make the search very targeted. The people doing these types of searches know exactly what they want (e.g. "used black high heel shoes"). These keywords are much less competitive and are easier to rank for on search engines. The downside is that they receive a great deal less volume of searches per month. In terms of traffic, you will need to have several #1 rankings for specific keywords to equal one #1 ranking broad keyword.