The backbone of all modern removable chip based storage devices is a memory chip capable of multiple read write cycle with high reliability. This form the heart of all USB flash drives what ever be the name. Pen drives is the name given to a category of USB flash drives which have a unique pen like shape with a lot of additional features. Since 1998 when IBM first invented the USB flash drive they got instant acceptability as people were fed up using those ever failing floppies and the compact disks which were pretty expensive at that point of time. All started from a 8mb capacity pen drive and now within the last one year the capacities commercially available has raced from 128 MB all the way upto 32 GB with the 64 GB and 80 GB in the pipeline though not very popular because of the high cost presently. But just like any other technology product these capacities will be obsolete very soon making way for much higher capacity drives and very shortly we may see a one terabyte drive on the shelf.
The first cousins of pen drive are the thumb drives, the chip sticks, the flash drives and the USB keys. Call it by whatever name the core technology remain the same. However in comparison with its cousins the pen drive come with a host of features making it a multi-utility Swiss knife amongst all flash drives.
Some of the advanced versions of pen drive have built in card readers to read the cards from other equipment like cameras and mobile phones for transfer of data directly to the huge capacity storage of the pen drive without any docking station or computer. Pen drives come in all sorts of shapes sizes and colors and have become the users choice of medium for transfer of large files from one place to another safely and securely.