hardware: the (physical) components used to make computer are referred to as hardware.
the purpose of this hardware is to facilitate the storage and processing of data under the direction of a stored program.
software: programs are known as software
bit (位): the smallest and most basic item(数据项) in a computer is a bit.
physically, a bit is a switch that can be open(0) or closed(1).
byte (字节): the grouping of 8 bits form a larger unit(单元), which is referred to as a byte.
each of the 8 bits is either 0 or 1, can represent any one of 256 distinct patterns. (from all open (00000000) to all closed (11111111))
这些pattern的每个都能表示字母表的一个字母，单字符(，等)，一位数字或多位数字。这样的模式集称为alphabetic code（字符码）比如，ASCII码
components must perform a minimum set of tasks and provide the capability to:
1 accept input.
2 display output.
3 store data & instructions(指令).
4 perform arithmetic & logic operations.
5 monitor, control and direct the overall operation and sequencing the system.
RAM(random access memory): 随机存取存储器，易失，电源切断存储内容会丢失。
ROM(read only memory): 只读存储器，不易失，电源切断不丢失。
CPU(central processing unit)
程序：program
编程：programming
编程语言：programming language
机器语言/可执行程序：machine language a.k.a executable program
汇编语言：assembly language 通过汇编器 翻译成机器语言
低级语言：low-level language 包括 汇编、机器
高级语言：high-level language C/C++/VB/Java
源程序/代码：source program/code
过程语言：procedural language
过程，接收数据作为输入，用某种方式转化数据，产生特定结果作为输出
在C中，过程称为function函数。
面向对象语言：object-oriented language
随着GUI的发展，屏幕上每个窗口都可以看成是与颜色、位置、大小等特性有关的对象。
C++基本属性，继承、多态、封装。
应用软件：application software
系统软件：system software
操作系统：operating system
算法：algorithm is defined as a step-by-step sequence of instructions that describes how the data are to be processed to produce the desired outputs.
ASCII (American Standard Code for Information Interchange)，美国标准信息交换代码。是基于拉丁字母的一套电脑编码系统。
http://baike.baidu.com/view/15482.htm
二进制
http://baike.baidu.com/view/18536.htm
八进制
http://baike.baidu.com/view/234126.htm
十进制
http://baike.baidu.com/view/359301.htm
十六进制
http://baike.baidu.com/view/230306.htm