Page 21 - IT_V5.0_Class8
P. 21
Pen Drive
A pen drive is a small, portable data storage device that uses flash memory
and is integrated with a USB (Universal Serial Bus) connector. It is a small,
portable storage device that can be easily carried in a pocket or on a
keychain. It connects to any computer or device with a USB port. Flash
drives have different storage sizes, from a few megabytes to over 1 terabyte.
Memory Card: It is commonly known as a multimedia memory card. It is
very small in size, usually 1–1.5 inches. These are used in mobile phones and
digital cameras. You need to have a card reader to read the data stored on
the memory card.
Measuring Unit for Memory 8 bits 1 Byte
The basic unit for measuring the memory of a computer is 1024 Bytes 1 KiloByte(KB)
byte. A byte consists of a group of eight bits, for example,
1024 KB 1 MegaByte(MB)
10001011, i.e., 1 byte equals 8 bits. A group of 4 bits is
1024 MB 1 GigaByte(GB)
known as a nibble (half a byte), for example, 1001 i.e., 1
nibble equals 4 bits or 10101011 is 2 nibbles equal to 1 Byte. 1024 GB 1 TeraByte(TB)
To represent huge data, we have different units to measure, 1024 TB 1 PetaByte(PB)
as listed below: 1024 PB 1 ExaByte(EB)
Software 1024 EB 1 ZettaByte(ZB)
It is a set of instructions given to a computer to perform tasks. For example, in a mobile phone,
the device is the hardware, and the apps installed are the software. Computer software is broadly
classified as system software and application software.
System Software
System software controls the functions of a computer, acting as an intermediary between hardware
and user applications. It manages hardware resources and ensures smooth communication
between components. The main types of system software are Operating Systems, Device Drivers,
and Utility Software.
Operating Systems: The operating system acts as an intermediary between users and
computer hardware, ensuring smooth communication and coordination of system resources
like the CPU, memory, storage, input/output devices, and network connections. Examples
include Windows, macOS, Linux, Unix, Android, and Ubuntu.
Fundamentals of Computer 19

