The records are very easy to use. I did a search for Moses Rosenbaum, who I knew died young sometime shortly before 1920. I found the record of Moses Rosenbaum who died on 29 November 1919 at the age of less than one year. From the index (shown below) we find some great information.
We now know that he was the son of Solomen Rosenbaum and Mabel Camilla Healey who lived at 52 Green S. E. We also know that he was buried on 1 December 1919 at Adas Israel Cemetery. We also have the option of looking at the original document by clicking on the View the Document in the upper right hand corner of the image above. That will take us to the original death certificate (as shown below).
This database can be found by clicking on the following link. District of Columbia Deaths, 1874-1959. As with all FamilySearch databases it is free for all.