What is difference between a WINS server and a DNS server?

For a lot of people, the relationship
between WINS and DNS is a bit of a mystery, but we are hoping to clear things up with
your question.
Firstly, DNS refers to ‘Domain Name Server,’ while WINS refers to ‘Windows Internet
Name Service’ – both are used to resolve names, but in a very different way!
To help explain, I’m going to use an example that will ensure you get the right picture on
each of these services.
Consider a file server by the name ‘Jupiter,’ and the following two commands:
1. Ping Jupiter.space.net
2. Net use * \jupiter mainshare
The two above commands should look familiar. The first one simply sends a ping (icmp
echo) packet to our file server, ensuring it’s alive, while the second command calls the
same server (Jupiter) in order to connect to a shared folder named ‘mainshare.’
While both commands are referring to the same name (Jupiter), the difference between
them is important.
Ping here uses DNS to resolve Jupiter.space.net to an IP address, e.g 204.45.12.1, while
the ‘net use’ command make use of WINS to resolve the NetBIOS name ‘Jupiter’ to an IP
address.
So you might be wondering why are there two different services essentially performing
the same job?
The answer is that each of these services relies on different protocols – they simply work
in a very different way.
WINS is an essential part of the Microsoft networking topology. In the older days, you
were required to run a WINS server in order to avoid name resolution problems within a
Windows network. The NetBIOS (Windows machine names) protocol back then would
only work on the NetBEUI transport protocol. If you ever ran Windows 95, you’d
remember the NetBEUI protocol was always present in your networking properties,
where as TCP/IP was optional.
Today, DNS has replaced WINS, since Microsoft made changes to NetBIOS, allowing it
to use the TCP/IP stack to perform its job (NetBIOS over TCP/IP) and most DNS servers
are able to handle NetBIOS requests. This is why WINS servers are becoming lesser day
by day.
In short, DNS maps TCP/IP host names to IP addresses and WINS maps NetBIOS host
names to IP addresses.