A DSL wireless router is made specifically for DSL broadband connections. In the UK, the main kind of DSL broadband is ADSL (Asymmetric Digital Subscriber Line).
The term DSL and ADSL is generally used interchangeably in the UK. If you have ADSL broadband, then you need an ADSL or DSL wireless router. If you have cable broadband, then you will need a cable wireless router.
See wireless ADSL router page for more information about wireless DSL routers.