Introduction - Java Software Solutions: Foundations of Program Design - page 50

Summary of Key Concepts

A computer system consists of hardware and software that work in
concert to help us solve problems.

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The CPU reads the program instructions from main memory, executing
them one at a time until the program ends.

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The operating system provides a user interface and manages computer
resources.

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As far as the user is concerned, the interface is the program.

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Digital computers store information by breaking it into pieces and repre-
senting each piece as a number.

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Binary is used to store and move information in a computer because the
devices that store and manipulate binary data are inexpensive and reliable.

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There are exactly 2 N permutations of N bits. Therefore, N bits can repre-
sent up to 2 N unique items.

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The core of a computer is made up of main memory, which stores pro-
grams and data, and the CPU, which executes program instructions one at
a time.

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An address is a unique number associated with a memory location.

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Main memory is volatile, meaning the stored information is maintained
only as long as electric power is supplied.

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The surface of a CD has both smooth areas and small pits. A pit repre-
sents a binary 1 and a smooth area represents a binary 0.

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A rewritable CD simulates the pits and smooth areas of a regular CD by
using a coating that can be made amorphous or crystalline as needed.

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The fetch-decode-execute cycle forms the foundation of computer
processing.

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A network consists of two or more computers connected together so that
they can exchange information.

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Sharing a communication line creates delays, but it is cost effective and
simplifies adding new computers to the network.

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A local-area network (LAN) is an effective way to share information and
resources throughout an organization.

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The Internet is a wide-area network (WAN) that spans the globe.

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Every computer connected to the Internet has an IP address that uniquely
identifies it.

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