Book
From Wikipedia, the free encyclopedia

Before the invention and adoption of the printing press, almost all books were copied by hand, making books expensive and comparatively rare.
A book is a set or collection of written, printed, illustrated, or blank sheets, made of paper, parchment, or other material, usually fastened together to hinge at one side. A single sheet within a book is called a leaf, and each side of a leaf is called a page. A book produced in electronic format is known as an e-book.
Books may also refer to a literature work, or a main division of such a work. In library and information science, a book is called a monograph, to distinguish it from serial periodicals such as magazines, journals or newspapers. The body of all written works including books is literature.
In novels, a book may be divided into several large sections, also called books (Book 1, Book 2, Book 3, etc).
A lover of books is usually referred to as a bibliophile, a bibliophilist, or a philobiblist, or, more informally, a bookworm.
A store where books are bought and sold is a bookstore or bookshop. Books can also be borrowed from libraries or obtained for reading through the practice of BookCrossing.

Pencil
From Wikipedia, the free encyclopedia

A pencil is a writing or drawing instrument consisting of a thin stick of pigment (usually graphite, but can also be coloured pigment or charcoal) and clay, usually encased in a thin wood cylinder, though paper and plastic sheaths are also used. Pencils are distinct from pens, which use a liquid marking material.

Caculator
From Wikipedia, the free encyclopedia

A calculator is device for performing mathematical calculations, distinguished from a computer by its having a limited problem solving ability and an interface optimized for interactive calculation rather than programming. Calculators can be hardware or software, and mechanical or electronic, and are often built into devices such as PDAs or mobile phones.

Modern electronic calculators are generally small, digital, (often pocket-sized) and usually inexpensive. In addition to general purpose calculators, there are those designed for specific markets; for example, there are scientific calculators which focus on advanced math like trigonometry and statistics, or even have the ability to do computer algebra. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.

Photocopier
From Wikipedia, the free encyclopedia

A photocopier (or copier) is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat. (Copiers can also use other output technologies such as ink jet, but xerography is standard for office copying.)

Xerographic office photocopying was introduced by Xerox in the 1960s, and over the following 20 years it gradually replaced copies made by Verifax, Photostat, carbon paper, mimeograph machines, and other duplicating machines. The prevalence of its use is one of the factors that prevented the development of the paperless office heralded early in the digital revolution.

Photocopying is widely used in business, education, and government. There have been many predictions that photocopiers will eventually become obsolete as information workers continue to increase their digital document creation and distribution, and rely less on distributing actual pieces of paper. However, photocopiers are undeniably more convenient than computers for the very common task of creating a copy of a piece of paper.