(i) A touch screen is a display device that allows the user to interact with a computer by using the finger.
(ii) It can be quite useful as an alternative to a mouse or keyboard for navigating a graphical user interface (GUI).
(iii) Touch screens are used on a wide variety of devices such as computer and laptop, monitors, smart phones, tablets, cash registers, and information kiosks.
(iv) Some touch screens uses a grid of infrared beams to sense the presence of a finger instead of utilizing touch-sensitive input.

(i) The ALU is a part of the CPU where various computing functions are performed on data.
(ii) The ALU performs arithmetic operations such as addition, subtraction, multiplication, division and logical operations.
(iii) The result of an operation is stored in internal memory of CPU.
(iv) The logical operations of ALU promote the decision-making ability of a computer.

Nano-technology is an engineering, science, and technology that develops machines or works with one atom or one molecule that is 100 nanometers or smaller.

(i) IC is short for Integrated Circuit or Integrated Chip.
(ii) The IC is a package containing many circuits, pathways, transistors, and other electronic components all working together to perform a particular function or a series of functions.

Punch cards also known as Hollerith cards are paper cards containing several punched or perforated holes that were punched by hand or machine to represent data.