<s>
A	O
network	B-Device
host	I-Device
is	O
a	O
computer	O
or	O
other	O
device	O
connected	O
to	O
a	O
computer	B-Architecture
network	I-Architecture
.	O
</s>
<s>
A	O
host	O
may	O
work	O
as	O
a	O
server	B-Application
offering	O
information	O
resources	O
,	O
services	O
,	O
and	O
applications	O
to	O
users	O
or	O
other	O
hosts	O
on	O
the	O
network	O
.	O
</s>
<s>
Hosts	O
are	O
assigned	O
at	O
least	O
one	O
network	B-Protocol
address	I-Protocol
.	O
</s>
<s>
A	O
computer	O
participating	O
in	O
networks	O
that	O
use	O
the	O
Internet	B-Protocol
protocol	I-Protocol
suite	I-Protocol
may	O
also	O
be	O
called	O
an	O
IP	B-Device
host	I-Device
.	O
</s>
<s>
Specifically	O
,	O
computers	O
participating	O
in	O
the	O
Internet	O
are	O
called	O
Internet	B-Device
hosts	I-Device
.	O
</s>
<s>
Internet	B-Device
hosts	I-Device
and	O
other	O
IP	B-Device
hosts	I-Device
have	O
one	O
or	O
more	O
IP	B-Protocol
addresses	I-Protocol
assigned	O
to	O
their	O
network	O
interfaces	O
.	O
</s>
<s>
The	O
addresses	O
are	O
configured	O
either	O
manually	O
by	O
an	O
administrator	O
,	O
automatically	O
at	O
startup	O
by	O
means	O
of	O
the	O
Dynamic	B-Protocol
Host	I-Protocol
Configuration	I-Protocol
Protocol	I-Protocol
(	O
DHCP	B-Protocol
)	O
,	O
or	O
by	O
stateless	B-Protocol
address	I-Protocol
autoconfiguration	I-Protocol
methods	O
.	O
</s>
<s>
Network	B-Device
hosts	I-Device
that	O
participate	O
in	O
applications	O
that	O
use	O
the	O
client	B-Operating_System
–	I-Operating_System
server	I-Operating_System
model	I-Operating_System
of	O
computing	O
,	O
are	O
classified	O
as	O
server	B-Application
or	O
client	B-Protocol
systems	O
.	O
</s>
<s>
Network	B-Device
hosts	I-Device
may	O
also	O
function	O
as	O
nodes	O
in	O
peer-to-peer	O
applications	O
,	O
in	O
which	O
all	O
nodes	O
share	O
and	O
consume	O
resources	O
in	O
an	O
equipotent	O
manner	O
.	O
</s>
<s>
In	O
operating	B-General_Concept
systems	I-General_Concept
,	O
the	O
term	O
terminal	B-General_Concept
host	I-General_Concept
denotes	O
a	O
time-sharing	B-General_Concept
computer	O
or	O
multi-user	B-Operating_System
software	I-Operating_System
providing	O
services	O
to	O
computer	B-General_Concept
terminals	I-General_Concept
,	O
or	O
a	O
computer	O
that	O
provides	O
services	O
to	O
smaller	O
or	O
less	O
capable	O
devices	O
,	O
such	O
as	O
a	O
mainframe	B-Architecture
computer	I-Architecture
serving	O
teletype	O
terminals	O
or	O
video	B-General_Concept
terminals	I-General_Concept
.	O
</s>
<s>
Other	O
examples	O
of	O
this	O
architecture	O
include	O
a	O
telnet	B-Protocol
host	O
connected	O
to	O
a	O
telnet	B-Protocol
server	B-Application
and	O
an	O
xhost	B-Device
connected	O
to	O
an	O
X	B-Operating_System
Window	I-Operating_System
client	I-Operating_System
.	O
</s>
<s>
The	O
term	O
Internet	B-Device
host	I-Device
or	O
just	O
host	O
is	O
used	O
in	O
a	O
number	O
of	O
Request	O
for	O
Comments	O
(	O
RFC	O
)	O
documents	O
that	O
define	O
the	O
Internet	O
and	O
its	O
predecessor	O
,	O
the	O
ARPANET	O
.	O
</s>
<s>
RFC	O
871	O
defines	O
a	O
host	O
as	O
a	O
general-purpose	O
computer	O
system	O
connected	O
to	O
a	O
communications	O
network	O
for	O
"	O
...	O
the	O
purpose	O
of	O
achieving	O
resource	O
sharing	O
amongst	O
the	O
participating	O
operating	B-General_Concept
systems	I-General_Concept
...	O
"	O
</s>
<s>
While	O
the	O
ARPANET	O
was	O
being	O
developed	O
,	O
computers	O
connected	O
to	O
the	O
network	O
were	O
typically	O
mainframe	B-Architecture
computer	I-Architecture
systems	O
that	O
could	O
be	O
accessed	O
from	O
dumb	O
terminals	O
connected	O
via	O
serial	B-Protocol
ports	I-Protocol
.	O
</s>
<s>
Since	O
these	O
terminals	O
did	O
not	O
host	O
software	O
or	O
perform	O
computations	O
themselves	O
,	O
they	O
were	O
not	O
considered	O
hosts	O
as	O
they	O
were	O
not	O
connected	O
to	O
any	O
IP	B-Protocol
network	I-Protocol
,	O
and	O
were	O
not	O
assigned	O
IP	B-Protocol
addresses	I-Protocol
.	O
</s>
<s>
User	O
computers	O
connected	O
to	O
the	O
ARPANET	O
at	O
a	O
packet-switching	B-Protocol
node	I-Protocol
were	O
considered	O
hosts	O
.	O
</s>
<s>
A	O
network	B-Protocol
node	I-Protocol
is	O
any	O
device	O
participating	O
in	O
a	O
network	O
.	O
</s>
<s>
A	O
host	O
is	O
a	O
node	O
that	O
participates	O
in	O
user	O
applications	O
,	O
either	O
as	O
a	O
server	B-Application
,	O
client	B-Protocol
,	O
or	O
both	O
.	O
</s>
<s>
A	O
server	B-Application
is	O
a	O
type	O
of	O
host	O
that	O
offers	O
resources	O
to	O
the	O
other	O
hosts	O
.	O
</s>
<s>
Typically	O
a	O
server	B-Application
accepts	O
connections	O
from	O
clients	B-Protocol
who	O
request	O
a	O
service	O
function	O
.	O
</s>
<s>
Every	O
network	B-Device
host	I-Device
is	O
a	O
node	O
,	O
but	O
not	O
every	O
network	B-Protocol
node	I-Protocol
is	O
a	O
host	O
.	O
</s>
<s>
Network	B-Device
infrastructure	I-Device
hardware	I-Device
,	O
such	O
as	O
modems	B-Application
,	O
Ethernet	B-Protocol
hubs	I-Protocol
,	O
and	O
network	B-Protocol
switches	I-Protocol
are	O
not	O
directly	O
or	O
actively	O
participating	O
in	O
application-level	O
functions	O
,	O
and	O
do	O
not	O
necessarily	O
have	O
a	O
network	B-Protocol
address	I-Protocol
,	O
and	O
are	O
not	O
considered	O
to	O
be	O
network	B-Device
hosts	I-Device
.	O
</s>
