Comment by shoebappa

While there are very confused and layered interpretations of what REST is, the reason it is important is that many of the Web Services APIs that preceded this trend used HTTP merely as a transport, but ignored so many of HTTP's features. This lead to them being difficult to use without bulky libraries. By using more of HTTP's features or basically HTTP as the API, it greatly simplifies and opens up possibilities and the tools that can interact with the API.