No cell phone is complete without a special device called a SIM card. Today, thanks to developments in the field of cellular communications, there are several different types of SIM cards.
A SIM card (the abbreviation SIM stands for Subscriber Identity Module) contains a lot of important data that is necessary to connect to a signal. At the same time, it restricts the phone to a specific carrier or region.
The main task of a SIM card is to store account information, which enables the user to easily and easily change mobile phones without changing their account. You just need to rearrange the SIM card to another phone. To accomplish this task, the SIM card is equipped with a microprocessor with software and data with card identification keys.
In addition, SIM cards can store additional information - a list of user contacts, a list of phone calls, text of SMS messages. Although in modern phones, such data is already recorded in the memory of the phone itself, and not on the SIM card.
Mini SIM card
Few of today's users have found the "big SIM", which was used in the first cell phones and resembled a credit card in size. After all, today a mini SIM-card, most often referred to simply as a SIM-card, is almost universally installed. It has dimensions of 25x15x0, 76. This standard card can store up to 250 contacts, as well as information related to cellular operators.
Micro SIM and Nano SIM cards
Micro SIM-card has an even smaller size - 15x12x0, 76. This standard was proposed by Apple and is used today in the iPhone 4, 4S and in all generations of iPads. Its main difference is that a significant part of the space around the perimeter of the card was removed from it and only a contact chip was left for connecting to the phone. If you need a Micro SIM card instead of a SIM card, you can purchase a special adapter that allows you to use smaller cards in a standard phone. However, the Mini SIM can be easily cut and turned into a Micro SIM, since the built-in functionality of both cards is the same.
With the advent of Micro SIM, it seemed that it would be used for a long time in iPhones or iPads. But with the development of the new iPhone 5, the developers managed to cut the size of the card even further and create a Nano SIM card. At first glance, the size of the new generation card has not changed much (9x12), but it has become almost twice lighter and thinner. The Nano SIM is also 15% thinner than the previous SIM. So cutting off a regular card for Nano SIM is now very problematic.
