# Topic map > A topic map is a standard for the representation and interchange of knowledge, with an emphasis on the findability of information. > > – [Topic map - Wikipedia](https://en.wikipedia.org/wiki/Topic_map) > Topic maps were originally developed in the late 1990s as a way to represent back-of-the-book index structures so that **multiple indexes from different sources could be merged**. > > – [Topic map - Wikipedia](https://en.wikipedia.org/wiki/Topic_map)