I can see three different, living, products in this field:
1. ADSL router which is an ADSL gateway with built-in ADSL Modem ( Two
in one), it might have also a 4 port Ethernet switch ( Three in one)
and recently you can find a wireless Access Point also in the same
device ( Four in one!),
ADSL Routers come with one (Ethernet) 10/100Mps RJ-45, 8 wires port and
one (Telephone) RJ-11 port at minimum!.
ADSL Router is all you need to have broadband Internet access and
sharing. You hook it to your ADSL telephone line from one side and to
your computer or network (Ethernet Switch) from the other side.
ADSL telephone line -------- ADSL Router ------------- Network or
2. ADSL gateway which is stand alone unit with two Ethernet, RJ-45, 8
wires ports, it might have a 4 port Ethernet switch (Two in one) and it
might have also a wireless Access Point ( Three in One).
You always need an ADSL modem with the ADSL gateway to have broadband
Internet access and sharing.
ADSL telephone line ----------- ADSL Modem -----------ADSL gateway
------------- Network or Computer .
3. ADSL modem ( it looks the same as an ADSL Router) with one
(Ethernet) port, 8 wires and one (Telephone) RJ-11, I never seen an
ADSL modem with 4 port switch or wireless Access Point.
An ADSL modem can be connected to a single PC or ADSL Gateway for
ADSL telephone line ------------ ADSL Modem -------------Computer
It's very confusing to figure out if a device is ADSL Router or ADSL
modem ........... always check the model No. and go to the vendor's web
site and products to figure out which of which.
The other professional way is to login to that device using your web
browser to figure out that ID.