Storage-It is the digital space where user can keep data like apps, music , photo, video, documents etc for further use. In a smart phone there are different types of storage system available according to their requirement. SIM card is also a storage but it can only store some simple data like massages, contact number etc as it has a low storage space and limited electronic circuit. Other different types storage are-RAM, ROM, external memory. RAM and ROM comes within the smartphone with onboard different storage capacity. Though a part of ROM is left for user to save some data, sometimes it’s not enough for that for user. So, there is require an extra space to save the data. We can get this as an external memory card.

RAM-Random access memory in short RAM is a volatile storage medium. Its main function is to keep ready the data or application in it from the main storage so that when the data or application is in use, we don’t have to go for main storage again and again hence we can access quickly. The data are store in it when the phone is in work. And the data erase itself after a power cut.                                                                                                                                                   Higher storage capacity RAM is better in performing multitask smoothly.

ROM- ROM in short Read only memory is a medium of permanent or semi-permanent storage. It is non-volatile in nature means the data stored in it does not erase due to power cut.                            In smartphone it is also known as internal memory. Some of its storage filled with the smartphone’s operating system software and apps. The remaining storage is left free for the user as internal storage to store the data, picture, multimedia etc.                                                                The higher number of GB is better for store more multimedia and data.For a smartphone minimum 32 GB is preferable because 7-9 GB out of 32 GB  will capture by phone application and operating system itself and remaining storage will left for user to use.