Happiness is one of those traits which is described as both a mental and emotional state. For example, you can mentally be happy at an event or for someone else while your overarching mood is sad. However, being happy is also an emotional state where we feel genuine joy coursing through us. It is often hard to capture happiness and to bottle it. However, the state can lead to higher levels of contentment, which is something that is more sustainable in the longer term. Of course, it is an entirely subjective matter, and what makes one person happy may be very different from how someone else might think about it.