DNS

• DNS is one of the most crucial parts of the Internet and provides the core functionality in resolving hostnames to IP addresses. For data to be transferred from one host to another, they must know each other's IP addresses. Hostnames are used because they are easier to remember, but they must be resolved into an IP address before data can be transferred. DNS servers are used to maintain a list of DNS records and clients query these servers when they need to look up the IP address of a particular hostname.
  
  

WINS

• WINS is a Microsoft protocol that is used to resolve NetBIOS names to their respective IP addresses. Since NetBIOS is rarely used in modern networking, WINS is not used as much as it used to be and, in some networks, not used at all. A NetBIOS name is similar to a hostname, except there are no subdomains or suffixes. An example of a DNS hostname is "technet.Microsoft.com," an example of a NetBIOS name is "server1". As with DNS, WINS uses a server to maintain a list of names and IP addresses.
  
  

Differences

• The vast majority of applications and services that require Internet connectivity will use DNS to resolve hostnames to IP addresses. Common examples of these are email, web and ftp. WINS, on the other hand, is not used on the Internet (except in very rare cases) and is used to resolve a local area network NetBIOS name to an IP address. A NetBIOS name is therefore only relevant within its own local area network. NetBIOS names can be resolved without a WINS server by the use of network broadcasts; this does pose problems however, in networks with more than one subnet.
  
  

Usage

• NetBIOS is considered to be a legacy protocol and is often only used to provide resolution services for older or legacy applications. In most modern networks that use Active Directory, WINS is not used unless older clients (pre-Windows 2000) are being used. DNS can be used in a local network in place of WINS and provide better scalability for name resolutions, but in special cases WINS is still required.