Why is my cell phone memory cards in mobile phones will also be able to read format. How the computer …

Why is my cell phone memory cards in mobile phones will also be able to read format.Say how the computer is not formatted?
Is no memory card reader or useless?
I have 2 memory card a 1G 1 is the 512 is the first
.Memory card format on the phone.But no computer formatted prompted the second
; 512M I get there (movie category) on the memory card reader .This is a film inside the card reader 3 days before the download.On the phone to the movies.Computers were not prompted to format .1 G of the same.M a number of mobile phone format.Inserted in the computer M has on many occasions.Internet-for-4 a replacement for the M-Taiwan
more than a third of .512 M card in mobile phones to the movies.However, on the card reader plugged into a computer format did not prompt the .1 G I was using a mobile phone format The number of M.Or computer format not prompted

This reader is very simple problem or suffer the Shuaiguo Damage over a reader will be able to change the format must be formatted in the FAT format on a computer click on the line on what format the line