through it multithreading concept

Exchange Server is a server which is designed to perform as 
a mail Server. which enables users tosend mail to others

Domain server is a server which holds a group of domains

Your set up might have been not done well.
Make sure you have added tomcat root directory path in the 
CATALINA_HOME environment variable and added the bin path in
the path variable.

you must set path for java up to bin

Start it up using the console so that the screen would not 
disappear. Then read the errors shown on the screen

yes

a server is an computer which manager all the network 
resoures and make avilable for athourised user.

Server is an administrator system on the network which is 
capable of serving the resources, files, folders, printer, 
internet sharing etc to the client systems

A server is a program which provides services to the clients
or other users .Servers are vendor specific It also
implements some clients APIs

A computer or device on a network that manages network 
resources. For example, a file server is a computer and 
storage device dedicated to storing files. Any user on the 
network can store files on the server. A print server is a 
computer that manages one or more printers, and a network 
server is a computer that manages network traffic. A 
database server is a computer system that processes 
database queries. 
Servers are often dedicated, meaning that they perform no 
other tasks besides their server tasks. On multiprocessing 
operating systems, however, a single computer can execute 
several programs at once. A server in this case could refer 
to the program that is managing resources rather than the 
entire computer.

A server is a master of network which we cantrol to the 
network.

a server handles the http protocols ,
when a server resieves a request from http ,then it erponse 
with it such as sending a html page

Server is a service provider to clients system, for example sending and receiving mail is service which is provided by mail server and.If we want any special services that will be provided by servers only.

Server is an administrator system on the network which is 
capable of serving the resources, files, folders, printer, 
internet sharing etc to the client systems

As the name itself reveals that a system which is used to provide services for the Authorized clients( Users ).

Tandem is a complete system. It's having it's own operating 
system is NonStop. database are nothing but flat files of 
enscribe like key-sequenced,entry sequence unstaructured 
files. we can use enforms to read enscribe files, we'll be 
having different utilities like FUP to read file data.

Web server (for development) that supports servlets 2.3 and
JSP 1.2 (Tomcat 4) or servlets 2.4 and JSP 2.0 (Tomcat 5).

The Architecture of Tomcat


Tomcat 4 is a complete rewrite of its ancestors. At the core
of this rewrite is the Catalina servlet engine, which acts
as the top-level container for all Tomcat instances.

 
With this rewrite of Tomcat comes an entirely new
architecture composed of a grouping of application
containers, each with a specific role. The sum of all of
these containers makes up an instance of a Catalina engine.

 
The following code snippet provides an XML representation of
the relationships between the different Tomcat containers:

 
<Server>
<Service>
<Connector />
<Engine>
<Host>
<Context>
</Context>
</Host>
</Engine>
</Service>
</Server>

 
This instance can be broken down into a set of containers
including a server, a service, a connector, an engine, a
host, and a context. By default, each of these containers is
configured using the server.xml file, which we describe
later in more detail.

The Server

The first container element referenced in this snippet is
the <Server> element. It represents the entire Catalina
servlet engine and is used as a top-level element for a
single Tomcat instance. The <Server> element may contain one
or more <Service> containers.

The Service

The next container element is the <Service> element, which
holds a collection of one or more <Connector> elements that
share a single <Engine> element. N-number of <Service>
elements may be nested inside a single <Server> element.
 
The Connector
 
The next type of element is the <Connector> element, which
defines the class that does the actual handling requests and
responses to and from a calling client application.

The Engine
 
The third container element is the <Engine> element. Each
defined <Service> can have only one <Engine> element, and
this single <Engine> component handles all requests received
by all of the defined <Connector> components defined by a
parent service.

The Host

The <Host> element defines the virtual hosts that are
contained in each instance of a Catalina <Engine>. Each
<Host> can be a parent to one or more Web applications, with
each being represented by a <Context> component.

 The Context
 
The <Context> element is the most commonly used container in
a Tomcat instance. Each <Context> element represents an
individual Web application that is running within a defined
<Host>. There is no limit to the number of contexts that can
be defined within a <Host>.