Merlot wine has few tannins which means it can be drunk when very young, without the need to be 'aged'.
Merlot is often added to Cabernet Sauvignon to bulk up it's rich fruitiness, but it is only in the last 30 years or so that producers have been selling Merlot on its own. Lots of Merlot comes from Bordeaux in France and from the valleys of California
When describing Merlot wines people often talk about the flavours of plums, cherries and chocolate. Like Cabernet Sauvignon you can sometimes get a lovely tea-like taste left over in your mouth, and this can sometimes be intensely orangey, which is a much sought after character.
Merlots are great because they seem to go with practically any food you care to mention. Many people like to serve a Merlot at slightly below room temperature.