Cell phones are part of the basic necessities nowadays.  A lot of person I know owns more than one cell phone.  If asked for the reason why they possess more than one cell phone, common answer is for them to have one official cell phone and one personal cell phone.  Especially in our country, where cell phone is a fad.  Almost all cell phone manufacturers entered our market and became successful.  Even fly by night companies that manufacture below standards are unfortunately reaching their fame.  

What is a cell phone?  Cell phone is also called mobile phone.  These are powerful handy device that allows communication at an instant.  A cell phone is operated by a subscriber identification module or what we call sim card.  A cell phone will not function without a sim card. Cell phones like computers have operating system too.  Basically for calling, but eventually evolved to messaging or text.  In the fast paced world of technology, cell phones were now made to do data transfers, emailing, internet browsing, and even mobile commerce.  It's really a powerful tiny device!

But even at the height of these technology advances, cell phones are still used for its primary purpose: to call.  Of course, no cell phones are without a cell phone number listing.  This device is capable of storing hundreds or even thousands of number.  A cell phone number listing is a cell phone feature where numbers and names are stored.  This is referred to as contacts.  Cell phones are not like fixed line telephones wherein you have to dial the numbers one by one each you call.  The cell phone number listing helps user to dial a contact in an instant.  With just one press and the dialing starts.  

Again, this cell phone feature is also passing development stages.  If before, cell phones are to instantly push the contact button, voices operating micro chips are now inserted in the cell phone framework.  This enables user not only to dial but to speak and say the contact name and then via voice recognition, the cell phone will immediately call the other party.  However, this feature will not operate without a cell phone number listing.  That is why, this cell phone number listing is very important.

Here's the catch.  Cell phone number listing cannot be done in an instant.  In order for the user to incorporate it in the contact menu, user needs to encode the list manually.  But once its there, calling a friend is just an instant.