How many types of servers you know , name them ?

Hardware:

HP Proliant, Dell PowerEdge, IBM BladeCenter, Fujitsu Primergy, NEC Express, Sun Sparc. (More types under each brand).

Server OS:

Windows (NT,2000,2003,2008,2012), Sun Solaris, Linux, Unix, MAC OS X.

Roles:

Mail server, Print server, DNS Server, DHCP server, File sharing server, FTP server, Web Server, Proxy server, SMTP server, SQL server, Terminal server, VPN server, Streaming media server, Archive server.

Applications:

100s of1000. Few well known are: Oracle server, Exchange server, Lotus Notes, Lync server.

DNS, DHCP, Mail, Web, FTP, TELNET, SSH, TFTP, Proxy, NMS, NFS, CIFS/SAMBA, XEN Server, Active Directory Server, Iptables, MySQL server   

Mail Server,SQL Server,File Server,Monitering Server,Windows Server,SVN Server,VMWare Server,Apache Server,Java Server,Time Server etc

HP proliant and Dell power Edge

Windows server2008 for AD,DNS,SQL Server

CENTOS Linux server for Email and proxy

Rack, Blade, Web server, FTP server, Application server, DHCP server

Dell, HP, Oracle, Linux (DHCP Server, File Server, Web Server, Proxy Server, Print Server, Application Server etc.)

The major differnce between servers are based on their processor make like Intel Based Servers, AMD Based Servers, SPARC Architecture & later they are divided into32-bit or64 bit processor.

hp, apache,citrix,windows,linix,