Samsung SGH-X427 - Manual (Page 168)

Glossary
163
PIN (Personal Identification Number)
Security code that protects the phone/SIM against
unauthorized use. The PIN is supplied by the service
provider with the SIM card. It may be a four to eight-digit
number and can be changed, as required.
Proxy Server
A server that resides between a web client, such as a web
browser, and a real Web server and acts as an intermediary
between them. When some people browse a web site, their
browser is not actually connecting to the web server. The
request from their browser goes to a proxy server, and the
proxy server makes the request to the web server.
A proxy server can improve performance for groups of
users because it cache the results of all requests for a
certain amount of time. If a user requests a web page that
it already fetched for another user, it returns the page
instead of forwarding the request to the Web server, which
can be a time-consuming operation.
PUK (PIN Unblocking Key)
Security code that protects the phone/SIM against
unauthorized use. The PIN is supplied by the service
provider with the SIM card. It may be a four to eight-digit
number and can be changed, as required.
Roaming
Use of your phone when you are outside your home area
(when traveling for example).