1. Introduction to Computers Part II

2. Software

3. Software
Computer software generally consists of three types: Programming Software Application Software System software

4. Programming Software
The programming software is commonly used computer software. As the name suggests, the software aids the programmers to write codes and programs for computers.

5. Application Software
Application Software is also known as an application or an "app", and is designed to help the user to perform singular or multiple related specific tasks. Examples of application software include: Microsoft Word, Microsoft PowerPoint, Adobe Photoshop, Adobe Illustrator etc.

6. System Software
System software is computer software designed to operate the computer hardware and to provide a platform for running application software
The most basic types of system software are: • The computer BIOS and device firmware, which provide basic functionality to operate and control the hardware connected to or built into the computer. • The operation system (prominent examples being Microsoft Windows, Mac OS X and Linux) and it also provides a platform to run high-level system software and application software
Utility software which helps to analyze, configure, optimize and maintain the computer.

7. Operating System
An operating system (OS) is software, consisting of programs and data, that runs on computers, manages computer hardware resources, and provides common services for execution of various application software.
The operating system is the most important type of system software in a computer system.
Without an operating system, a user cannot run an application program on their computer, unless the application program is self booting.
The operating system performs many essential tasks for your computer. 

It controls the memory needed for computer processes, manages disk space, controls peripheral devices, and allows you to communicate with the computer without knowing exactly how a computer works. Without an operating system, a computer is useless.
Examples of popular modern operating systems are: Linux, Mac OS X, Microsoft Windows and UNIX

8. Bits and Bytes

9. Binary Code
Computers use a special code of their own to express the digital information they process. It's called the BINARY CODE because it consists of only two symbols - 0’s and 1’s. (The "bi" in "binary" means two.)
Why 0’s and 1’s? Because those are the only two numbers you need to express the flow of electricity through a transistor. It's either on or it's off. On is 1, off is 0. Everything you say to a computer has to be put in terms of these two numbers.
People use all kinds of symbols, sounds, colors and body motions to express themselves. These expressions are, in a sense, codesﾑsignals we use to communicate with one another. Computers have a special code too, though it never changes and its not really a secret. Information in a computer can only be represented by one's and zero's. This code is called digital information. Why one's and zero's? Because those are the only two numbers you need to reflect the flow of electricity. Its either on, or its off. On is '1', off is '0'. Everything you say to a computer has to be put in terms of these two numbers.

11. Binary Code - BIT
For a computer to or respond to a command, it has to be translated into the only language a computer knows: the 0’s and 1’s of the binary number system. The 0’s and 1’s represent the on and off of the transistors.
What do you call one of these 0’s or 1’s? A bit. Which makes sense when you see how many of these bits it takes to represent a word, number, color, graphic or sound. They really are just a "bit" of something bigger.

12. How Computers Work With Pictures
Picture this. A computer is made up of millions of electronic switches (transistors). They're either on or off, open or closed. Now picture this. Your computer screen has hundreds of thousands of dots arranged in rows and columns. Each dot is a picture element or pixel. Each of these pixels displays some combination of red/green/blue according a device called a Video Graphic Array (VGA) The VGA translates binary-coded information (0s and 1s) into the color combinations required to make up an image on your computer screen.

13. Activity 1 and 2
TheCurriculum/EC_DigitalInformation/DILesson3 /DIL3_Activity1/
Visit this site and complete the activity. Once you complete this activity click NEXT to complete the second activity.

14. Binary Numbers
The binary system that computers use to store and process information is a base 2 system. It needs only two symbols, 0 and 1. In fact, "binary" comes from the Latin word for two. Compare this to the decimal system you use. The decimal system is a base 10 system. ("Decimal" comes from the Latin word for ten.) It has 10 symbols (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). In decimal (base 10) numbers, you have a 1s place, a 10s place, a 100s place, and so on, to represent value.
Hundreds
Tens
Ones 1 3

15. Binary Numbers
So how do you count in a binary system? How do you represent
numbers like 103?
The binary system has places or columns too. Because you're in base 2,
instead of each place being 10 times greater than the place before it,
each place is only double (2 times) the one before it.
256
128 64 32 16 8 4 2 1
Therefore, 103 = (conversion from decimal to binary)

16. Decimal to Binary Conversion
How do you convert a decimal number to binary code? To convert a decimal number to binary, first subtract the largest possible power of two, and keep subtracting the next largest possible power from the remainder, marking 1s in each column where this is possible and 0s where it is not. Example 1 - Convert decimal 44 to binary

17. More Examples

18. Converting Binary to Decimal
Let’s convert the binary number to a decimal number
Move through each digit of the binary number. If the digit is a 1, write its corresponding power of two below the line, under the digit. If the digit is a 0, write a 0 below the line, under the digit.

19. Converting Binary to Decimal
Add the numbers written below the line. The sum should be 155. This is the decimal equivalent of the binary number Or, written with base subscripts: = 15510

20. Examples

21. Bits and Bytes
Remember that a bit is a single numeric value, either 1 or 0. It takes eight bits to make up an individual character (letter, number, or symbol) used in the English language. Each individual character is called as a byte. Therefore, eight bits equal one byte.
Example: How many bits in the word ‘October’? There are 56 bits in the word October (7 letters x 8 bits in each character) = 56
Example: How may bytes in the word ‘October’? There are 7 bytes in the word ‘October’ because there are seven characters in the word October or if I know that there are 56 bits, then I know that 56÷8=7

22. What does 32-bit and 64-bit mean?
32-bit systems utilize data in 32-bit pieces while 64-bit systems utilize data in 64-bit pieces. In general, the more data that can be processed at once, the faster the system can operate.
There are several other advantages to a 64-bit system as well, most practically the ability to use significantly greater amounts of physical memory.
Most new processors today are based on the 64-bit architecture and support 64-bit operating systems. These processors are also fully compatible with 32-bit operating systems.Most editions of Windows 7 and Windows Vista are available in 64-bit format. Only Windows XP Professional is available in 64-bit. All editions of Windows 7, Windows Vista, and Windows XP are also available in 32-bit.

23. KB, MB, GB, TB
1 Kilobyte (KB) = 1,000 bytes (approximately 1/3 of a page of text)
1 Megabyte (MB) = 1,000 KB (approximately 365 pages of text)
1 Gigabyte (GB) = 1,000 MB (approximately 395,000 pages of text)
1 Terabyte (TB) = 1,000 GB (approximately 400 million pages of text)

24. Homework
Complete the homework questions that are posted online