Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)


iPhone unlock

See SIM lock.

SIM lock

(Subscriber Identity Module lock) A function in GSM cellphones that restricts the phone's use to a particular cellular carrier (a particular SIM card). SIM locks are used to ensure subscribers finish their service contracts when the phones are heavily subsidized by the carrier. SIM locked phones may be unlocked by entering a code.

Apple's iPhone brought the SIM lock into public view because of its original exclusivity in the U.S. with AT&T. However, iPhones were readily "unlocked" by hackers both in and outside the U.S., not only to use a different carrier, but to customize their appearance and download applications even before Apple debuted its App Store. In addition, Apple allowed the GSM iPhone to be sold without the SIM lock in Australia, Taiwan, Hong Kong and other regions where locked phones were either prohibited or a recipe for marketing failure. See SIM card and iPhone jailbreaking.

Personal Use Only

Before/After Your Search Term
iPhone generationiPhone versions
iPhone glovesiPhone vs. Android
iPhone jailbreakingiPhone X
iPhone modelsiPhone1
iPhone OS 1.0iPhone2
iPhone OS 2.0iPhone2G
iPhone OS 3.0iPhone3
iPhone SEiPhone3G
iPhone touchiPhone3GS
iPhone UDIDiPhone4

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
ProgrammingHealthcare IT
System design