A subscriber identification module, or SIM, card is a removable memory chip that stores a cell phone user’s account information. This information can include call logs, contact lists and sent and received text messages. While SIM cards can make upgrading to new phones and switching over to different phones simpler processes, the cards can also cause problems. This is especially relevant when it comes to Apple’s line of iPhone smartphones, which have notoriously suffered from SIM card problems in the past. Writer Bio
