An indexer creates an index, which is a methodical arrangement of records designed to enable users to locate information quickly. There are many types of indexers, but the primary types include book indexer, data indexer, and medical indexer. The general functions of these jobs are similar, but your specific duties in each of these careers may vary. For instance, as a data indexer, you may work on a computer to index, where a book indexer most likely does not work with technology except to type and print out the indexes they create. A medical indexer may or may not work with technology, but you need to have a general knowledge of medical terminology to be successful in this role.