Pen drive is a external data storage device which

 PEN DRIVE  &  CARDR EADER::

                                  

Pen drive is a external data storage device which is use for carry the data one computer to another computer and cardreader is out put device which is use to connect to the memory or other external data storage device etc.A USB flash drive is a  DATA STORAGE DEVICE that includes FLASH  MEMORY with an integrated Universal Serial Bus (USB) interface.USB flash drives are typically removable and rewritable.USB flash drives are often used for the same purposes for which floppy disk or CDs were used
 

                               

Pendrive and card reader connected to the computer USB slot. Pendrive made metal or plastic.the speed of a pendrive is  500kpps to 1.0mbps.it is use all over the world and it is portable to carry one place to another place.in pendrive there are present read and write head. we connected the pendrive with computer to store the data.

A flash drive presenst of a small printed circuit board  carrying the circuit elements and a USB connector, insulated electrically and protected inside a plastic, metal, or rubberized case which can be carried in a pocket or on a key chain, for example. The USB connector may be protected by a removable cap or by retracting into the body of the drive, although it is not likely to be damaged if unprotected.