H.R. versus H. Res

http://thomas.loc.gov/home/faqlist.html

How are bills identified? Are there different versions of bills?

There are four types of legislation: bills, joint resolutions, concurrent resolutions and simple resolutions. Any of these may be introduced in either chamber. They are identified as follows:

1. S. 123 - Bill originating in the Senate
2. S.R. 123 - Simple Resolution of the Senate
3. S.J.Res. 123 - Joint Resolution originating in the Senate
4. S. Con. Res. 123 - Concurrent Resolution originating in the Senate
5. H.R. 123 - Bill originating in the House
6. H.Res. 123 - Simple Resolution of the House
7. H.J.Res. 123 - Joint Resolution originating in the House
8. H.Con.Res. 123 - Concurrent Resolution originating in the House

http://thomas.loc.gov/home/faqlist.html