This really doesn't mean a whole lot, but TPP has a sort of weird fascination with seeing where and how his publications are cited. You don't want to be an example of "couldn't grab his butt with both hands", and so far so good, but it's interesting to find out what other people see in your publications, how they are used. Now a number of indexes have been proposed that allow you to make all sorts of bogus comparisons. Understand that you do some research, and then you write a paper in an attempt to publish it, and when that occurs, other people find out about your research and its results and conclusions with the result that they cite your work to show the background or rationale or similarities or differences to their work, but that takes time. The longer you publish the more your publications can be cited or ignored. The more you publish, the more your publications can be cited or ignored, and there is a domino effect because getting cited alerts other people to your publications. TPP published his 1st scientific paper nearly 40 years ago and has published regularly if not prolifically ever since. For the longest time my h-index was 17, meaning that 17 of my publications had at least 17 citations; some have more than a hundred. Really important papers get thousands of citations. Just recently my h-index went up to 18! To get a really high h-index you have to have a lot of papers with a lot of citations. That can be easier in some fields than in others depending on how much and how many people work in that field, and this does not count selfies (self-citation). People with 2 or 3 times as many publications may not have an h-index any higher than mine, and this then is why this could be used as a gauge of your impact on a field scientifically. A colleague and friend is in ornithology, and he's been prolific and important, and his h-index is 23. A couple of my super-star colleagues have h-indexes of 28 and 35. Both are in big fields, but both do very good research and are more prolific publishers. A really low index would suggest you have either few publications or lots of publications that only make a very minimal impact. My h-index may go up another notch or two ultimately as some newer publications begin to get into the literature, but not the stuff of a power-house.