There are a lot of words in the English language that appear to have the same meaning but in actually are quite different. A lot of people, however, remain oblivious to the difference in meaning and therefore use two words with apparently similar meanings interchangeably. It is only after they actually go through their meanings in a dictionary or come across their correct usage that they realise their mistake.
Terror and horror are among the pair of words that people confuse to be one and the same. In order to correct the mistake of using them interchangeably, it is important to understand the difference in their meaning and their apt usage.
Terror is basically an intense fear that a person feels when he anticipates something bad happening, whereas horror is an emotion that grips a person after he learns about or witnesses something bad happening. The latter is more of a feeling of revulsion in response to a disturbing event or occurrence.
Another thing that sets terror apart from horror is the nature of the two emotions. As mentioned before, horror relates to revulsion or disgust. Terror, on the other hand, relates with extreme fear and anxiety.
When a person is gripped by the fear that something bad is about to happen, he is said to be terrified, a word that relates to the human emotion of terror. However, when a person witnesses a really disturbing or unpleasing sight, he typically feels horrified, a word that relates to the human emotion of horror.
Another difference between the emotion of terror and horror is that the former relates to the emotion that a person feels when he is under an imminent danger, whereas the latter is the emotion that one feels upon looking at the damage or destruction that the danger has caused upon arrival.