Understanding Computers and the Internet

Computer Programming

06/18/14

A computer is an electronic device for storing and processing data, typically in binary form, according to instructions given to it in a variable program. A computer has two components: Software and Hardware.

Hardware: The hardware are the physical components that make up the computer system. Hardware is the machine, wiring, and other physical components of a computer or other electronic system.

• IDE - stands for Integrated Drive Electronics is a 40 pin interface that connects the hard disk to the mother board.
• SATA - Serial ATA or SATA connectors are the next generation hard drive technology, it will replace hard drives using IDE connectors.
• The Optical Disc Drive - Is a device that is used to read and write data from optical media such as Compact Disk (CD), DVD and Blu-Ray disc.
• Peripheral Component Interconnect Express (PCIe): is a computer expansion card standard that is designed to replace older bus standards. The PCIe has a better overall performance over the older type of video cards such as the AGP.
• Accelerated Graphics Port (AGP): is an interface specification that was developed by Intel Corporation. The AGP channel is 32 bits wide that runs at 66 MHZ.

Software: Software is a general term for the various kinds of programs used to operate computers and related devices. It gives the computers instructions in order to function. Computer instructions, data or anything that can be stored electronically is software.'

• Binary Code: A coding system using the binary digits 0 and 1 to represent a letter, digit, or other character in a computer or other electronic device. A binary code represents text or computer processor instructions using the binary number system's two binary digits, 0 and 1. A binary code assigns a bit string to each symbol or instruction.
• Binary System: Unlike the Decimal System, it uses 1's and 0's to represent information like letters, characters, numbers, etc...
• ASCII: ASCII stands for American Standard Code for Information Interchange. ASCII maps patterns of bits to display letters, decimals and characters that people can understand.

0.25.15

Fundamentals in Buying Computers and Technical Particulars:

• In buying computers, no matter what brand, the first thing you will see is the "Buyer Beware" or "Buzzwords". These things will tell you what are the things the product has and the specific "freebies" it has.
• Computers have price points to be careful with. Price points are the inexpensive prices that products have. They usually add up every time you buy more products with price points.     

Technical Particulars of a computer:

• In terms of Memory, computers contain Gigabytes for storage and Megahertz/Gigahertz for speed.
• Third party hardware are physical parts of a computer that you can by at a technical store and install the hardware to your computer, yourself.
• Virtual memory uses the mechanical hard disk to store memory when the RAM is filled with data.
• A processor (Like the i5 processor) can determine or enhance the computer's speed to process data per second.
• Computers can have two system units: GPU and CPU
• CPU: The main processor of the computer which functions all the systems inside the computer. Packed with RAM and other devices, the Central Processing Unit(CPU) can run multiple task simultaneously.
• GPU: The Graphics Processor displays photos, videos and other graphical featurea in the computer.
• Anything that makes the computer move causes it to decrease battery life.
• Graphical software Programs takes up more memory than non-graphical ones.
• Hard Disk Drives store data using Megahertz/Gigahertz. There are multiple kinds of disk drives. 

• IDE - stands for Integrated Drive Electronics is a 40 pin interface that connects the hard disk to the mother board.
• SATA - Serial ATA or SATA connectors are the next generation hard drive technology, it will replace hard drives using IDE connectors.
• The Optical Disc Drive - Is a device that is used to read and write data from optical media such as Compact Disk (CD), DVD and Blu-Ray disc.

07.02.15

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More on computer storage:

• Solid State Drive(SSD):
• Unlike mechanical storage devices, Solid State Drives store data electronically. SSD's have more capacities and more speed but they are also expensive. They are like the bigger and faster version of a USB. SSD'S are purely electrical and can store bigger data. Hardware safety is also a benifit in SSD's since they can't be harmed if your hardware is damaged. It's also possible that an SSD's don't generate much heat and lose data since they are software. SSD's also reduce boot time by 20 seconds. SSD's tell the computer how to store data through signals that SSD's release.
• Mechanical Drive Circuits: 
• They translate signals into voltage fluctuations and control the hardware then travels into the hard drive sections.   
• Logic boards/Motherboards
• The mother board is a special logic board that come in different colors. They run the entire computer and without it, your computer will fail. CPU's are attached to the motherboard as well as other hardware chips too. RAM and Expansion cards are also connected to the motherboard. The memory of the motherboard creates electrical fields to change the polarity of the motherboard's storage parts. The software signals the electronic pulses until it reaches its objective and represent data then reverses its polarity to rewrite data. All mechanical hard drives like SATA's and floppy disks all follow the same pattern. No matter how many reading disks are in a mechanical drive, they still follow the same pattern. 

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Reflection: Today I am done writing my notes for hardware. These notes on screen are actually summarized. I reduced the excessive examples that are in my notebook. I only wrote keypoints here to have fundamental knowledge of hardware.
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07/09/14

More about the Motherboard and it's parts.

The Motherboard contains different parts that keeps the computer running. They can contain expansion technology like:

• Processor: They contain pins which acts like wires to process and represent data. Processing pins aren't connected to each other but can still surge data.
• DIMMS/RIMMS: They help the processing pins operate data. The manufacturers commonly dictate what DIMMS or RIMMS are recommended in your computer.
• AGP Slot: The Accelerated Graphics Port (often shortened to AGP) is a high-speed point-to-point channel for attaching a video card to a computer system, primarily to assist in the acceleration of 3D computer graphics. It was originally designed as a successor to PCI-type connections for video cards.It accelerates your graphics port and PCI's to support 3d formats.
• Heat Sink: It is a device that is attached to a microprocessor chip to keep it from overheating by absorbing its heat and dissipating it into the air. Generally, a microprocessor's temperature should not run in excess of 50-55 degrees Celsius while under a full load. They can cool down the computer as much as possible. These machines can be either fans or liquid radiators.
• PCI Connectors: Use to attach hardware to the computer.

07.16.15
The Internet: 

• The internet is a signal that allows machines to communicate each other through trace routs. Trace routs allow machines to contact and trace your signals so servers can receive your request. I.P addresses in order to communicate with the server or variety of servers. Your machine's server request follow a series of steps which allows your request to end up in the server. Your request that goes into multiple servers start from an access point. Transferring requests from one server to another is called a "hop". "Latency" is the response time of your computer to communicate from server to server. The higher the latency, the slower your computer's response is. An I.P address is an indicator which locates your computer's current position. I.P v.4 addresses range from 0 - 255 bits which are 32 Octet bits. Octet bits are enough to connect  more than 4.2 billion devices. IP addresses come in "blocks" to connect multiple devices and websites. Network address translations share IP blocks or address to multiple devices to save more space than multiple ones. IP v.6 can have a space of 38 x 10^38 billion Octal bits. All computers connected to the internet are assigned in addresses which makes tracking it possible.

07.16.15
The Internet:

• Last time, we talked about the internet and things related to it. But now we will talk about:
• DNS Servers:
• DNS servers or Dynamic Name System, they act like address books which lets you view the domain name location. DNS appeares like .com, .org, .gov, etc... DNS returns and gives off addresses associated with the domain name. DNS determines load balance and redundancy in case it's unreachable. DNS lets your IP ask the server query in order to reach it and returns it's configurations to your computer once the requested data is accessed. Typing DNS is mucb easier than typing the IP address. Example is that typing www.Google.com is easier than 139.130.4.5 or 8.8.8.8. DNS can also return multiple IP configurations. Top level domains like .com, .org, .edu, .gov, are made of segments. Top level domains in recent years are expanded to allow other countries to exist it's specific domain location. Example is .tv from Tuvalu. It also possible to purchase domains within a domain level space. It also possible to purchase sub-domains which specifies the domain your requesting. The top level domains contacts the associated subdomains which nests the specific IP address and spreads all it's configurations and caches all it's configurations at a certain level of time.
• Server <-> Client model:
• Server - takes up data and gives it to the client. A server can operate a variety of servers and protocols, it serves data through a variety of ports and webpages it connects.
• Client - Requests data.

07/30/15

Multimedia
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Multimedia uses a combination of different content forms. Unlike with media that use only rudimentary computer displays such as text-only or traditional forms of printed or hand-produced material. Multimedia includes a combination of text, audio, still images, animation, video, or interactive content forms. As the name implies, multimedia is the integration of multiple forms of media. Multimedia composes of many forms while media consist of only one or two. Multimedia includes text, graphics, audio, video, etc. For example, a presentation involving multiple audio and video clips would be considered a "multimedia presentation." Educational software that involves animations, sound, and text is called "multimedia software." The use of computers to present text, graphics, video, animation, and sound in an integrated way. Long touted as the future revolution in computing, multimedia applications were uncommon due to the expensive hardware required in the mid-90's. With increases in performance and decreases in price, multimedia is now commonplace. Nearly all PCs are capable of displaying video. Multimedia may be broadly divided into linear and non-linear categories. Linear active content progresses often without any navigational control for the viewer such as a cinema presentation. Non-linear uses interactivity to control progress as with a video game or self-paced computer based training. Hypermedia is an example of non-linear content.

08.06.15

Security:  

• Deleted files
• Have you ever deleted files in your computer and thought they're lost forever? Well actually, deleted files don't disappear. Things that are deleted in your computer are just hidden in the hard drive with it's header erased making them recoverable. This can also also be insecure when you give or sell your computer to other people even though if your files are all deleted, they can still be recovered by the wrong hands. There are ways to secure your deleted files: You can either call a technician to replace the hard drive or do it yourself or destroy the hard drive literally (i.e Smashing it with a hammer or Burning it to ashes) The hard drive contains a file location system that basically describe the file and it's contents. When an item is deleted, only the header file is destroyed but the contents aren't. The contents without their header file are hidden in the hard drive allowing it to be merged by existing data. So remember that merely clicking "delete" on your file isn't sufficient to make it disappear. Modern computers involve fragmentation or scattering bits of information around your computer. De-fragmentation allows fragments of deleted data to be recovered and go out as either the original file or junk mail. Anyway there is also another way of deleting files permanently without smashing or replacing the hard drive. The method is to zero-out the file by using software such as www.dban.org.

• Cookies
• Pieces of information found in the internet are called cookies which also works the same way offline files do. Cookies though store your online information such as usernames and passwords. Individual servers give you cookies allowing you to use the same information over and over again on a particular website. Individual servers and websites doesn't stop giving you cookies which may be in the risk of session hijacking but cookies can be stopped by an option which disables cookies.
  

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08/13/15

• Session Hijacking:
• Are also known as cookie hijacking, these can exploit your computer session and gain unauthorized access without even accessing your computer physically. The dangers with cookie hijacking is that the hijacker can actually browse the internet with their victim's account information. An example of a session hijacking tool is  firesheep which allows you to hack cookies and take their information giving you unauthorized access to different network information. Cookie hijacking can also result to terminate your request and response to the server you're requesting. Another thing is that you can hijack cookies from anyone and anywhere. The servers that are associated with the cookie will allow you access the accounts you have on that server or particular set of servers. Hijacked cookies can send and use their cookies on their browsers and log in as their victim on a particular website and of course, hijacked cannot be detected by servers and makes the server assume that the cookie is from the original user. 
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• Spams:
• Annoying emails sending you messages like this: 
• "You won rewardz!!! Download now!" 
• Cheesy right? well these email/messages are called spams. Spams are irrelevant or inappropriate messages sent on the internet to a large number of recipients. Spamming usually involves sending information to millions of people about the things you sell. And believe it, some people fall for it(more like 1 in a million people). This isn't really a problem though you can just exit the annoying message or can you? Actually spammers use nasty tricks by embedding information in the close button that tells their spam message to send more
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