Tags are what WordPress calls is keywords. I attach a small number of tags to every post to help people navigate between content with the same keywords. Tags may be people (David Gauke say), organisations (The Howard League, Revolving Doors Agency), themes (women offenders, homelessness) or specific items (heroin, cocaine, ROTL). If you’re looking to research a particular issue, they can be invaluable.
As you can see the murder rate in the UK is the same as that in France and Ireland but substantially higher than that in Germany and Spain. The main standout fact is that Black US citizens are almost 8 times more likely to be murdered than their white fellow citizens.