There are two types of memories: Primary and Secondary.
The primary memory or the main memory is part of the main computer system. The processor or the CPU directly stores and retrieves information from it. This memory is accessed by CPU, in random fashion. That means any location of this memory can be accessed by the CPU to either read information from it, or to store information in it.
o The primary memory itself is implemented by two types of memory technologies. The first is called Random Access Memory (RAM) and the other is read only memory (ROM). A more appropriate name for RAM is RWM (Read Write Memory), the CPU can write and read information from any primary memory location implemented using RAM. The other part of primary memory is implemented using ROM which stands for Read Only Memory.
Primary memory is much faster and also it is more cost effective. But the secondary memory is much slower and also less costly. It stores the data permanently unless it is erased. The secondary memory is usually available in the form of floppy disk storage media, hard disk, CD, DVD, Pen drive (i.e. Mass storage devices), memory chips. A 5 and1/4 inch floppy disk typically stores 1.44 mb of data. The data on the floppy disk is organized in terms of tracks and sectors. Hard disk can have large capacity something like 80-300 GB's or higher. Hard disk itself is made up of, large number of platters. Hard disk is usually much faster compared to floppy disk. CD can store up to 750 mb of data. Information on CD ROM is organized in terms of a spiral track. A DVD is digital Versatile Disk and can store 4.6 Gigabyte of information. All these CD disk are usually write ones and read many times (if the disk is not multisession and re writable). So are the DVDs.
so as a conclusion, pen drive is a secondary type of memory, since it is a peripheral device and needs to be connected to the computer to retrieve the datas.
FLASH MEMORY is used in cell phones.
Second storage memory has 2 definitions, it's either the space in your hard drive that's not occupied by your files and operating system, or it could be portable memory like usb sticks, (flash drives) and CD's.
nonvolatile storage
Non-volatile storage
Flash memory consists of nonvolatile memory chips that can be used for storage by the computer or the user. Flash memory was introduced in 1984.
Primary storage includes Random access memory (RAM) which is fast and volatile. Secondary storage consists of devices like hard disk drives (HDD) and solid-state drives (SSD) which are slower but non-volatile, allowing data to be stored for longer periods even when the power is turned off.
A "flash stick" is another word for a USB flash drive. The term "flash" is used because it consists of flash memory data storage. Flash memory is is a non-volatile computer storage (computer memory that can retain the stored information even when not powered) that can be electrically erased and reprogrammed.
Flash drives, back up storage units
No.
No, its not an optical storage device.
For new computers it can be both.
secondary memories are the memories by which CPU proccesses his programs and application.