What is a RBG ?

 "RGB", stands for Red, Green, Blue one of the most popular color models. A spectrum of colors are created by mixing red green and blue light as seen in the simplified color model on the left. Notice that mixing red light and green light creates yellow light. It is important to remember that color light and color pigments are very different. The traditional color wheel for artists uses red, blue, and yellow pigment to create many colors. Mixing all colors results in a grey/brown pigment. However, light acts very differently. Just as a prism can divide white light into many colors, adding colored light produces white light as seen in the center of the model. Because of this RGB is referred to as an additive model because the light beams are added together.

History

The RGB model is, "is based on the Young–Helmholtz theory of trichromatic color vision, developed by Thomas Young and Hermann Helmholtz, in the early to mid nineteenth century, and on James Clerk Maxwell's color triangle that elaborated that theory (circa 1860)."Trichromacy occurs when animals possess three color receptacles within the eye. Humans and primates are trichromats and therefore respond well to color models based on tri-color sources. The image on the left shows the large variety of colors possible in this model.

Digital

Digitally each color is indicated by three bytes representing three numbers from 0-255. Each number is associated with a color intensity. Therefore the color [255,0,0] would be pure red, with red light emitted at the highest intensity and no green or blue light. Likewise one could guess that the color [255,255,255] is white, and (assuming a black monitor screen) the color [0,0,0] is black. Therefore the entire grey spectrum can be represented by three equal numbers, such as [126,126,126]. The color cube shows 3 dimensionally how changing these parameters results in a wider range of colors than shown in the 2 dimensional color wheels.
While the model is based on emitted light software converts and prints color images with no need for user input. Users should be aware that other models exist such as C,M,Y,K standing for Cyan, Magenta, Yellow, and Black. Converting between models may result in slightly altered color characteristics.
When using image editing software like photoshop it is possible to closely control the RGB values of each color and to save that assignment as a "swatch". This helps ensure color consistency which often cannot be detected by the human eye on a monitor but are apparent in print.

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What is Peer to Peer (P2P) ?

P2P

Peer to Peer (P2P) networking is a type of network architecture in which each machine on the network performs the tasks of a server and a client; each machine supplies and accesses each other's information. Rather than a centralized architecture in which many clients access a single server which uploads data to each client, a P2P network allows each machine to upload and download data from each other.
These types of networks gained popularity during the late 1990s/early 2000s with Napster, a free P2P music sharing service. Many companies began offering a similar service, and today there are still many popular P2P networks in existence. One of the most popular modern applications of the P2P model is file sharing, which can be used to share music, videos, and software. One file sharing protocol, BitTorrent, accounts for 43% to 70% of all internet traffic. It has, on average, at any given time, more active users online than Facebook and YouTube combined.
P2P networks are also found as part of "hybrid networks," in which clients access servers for information, as in a server-client network, and servers share information with each other, as in a P2P network.

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What is a Firewall ?

Firewall

Firewall is basically a defense system that blocks intruders on the internet from gaining access to your computer network. It acts as a "wall" that restricts the movement of data between the internet and your network, and vice-versa. Firewalls can be implemented via either hardware or software, or both.

Use:
A firewall serves two primary purposes. First, it protects computer systems and networks from malicious activity coming across internet connections. Second, it also provides computer network administrators with control over the types of communication that can be conducted over internet connections within a specific computer network. In the first purpose, the firewall acts as a communications filter which can stop those malicious communications from ever reaching your computer in the first place. The second purpose is where a firewall can be programmed with specific, customized rules that may restrict employees from visiting websites that are unrelated to business goals or that may pose security risks.

How It Works

There are basically two types of firewalls, these are hardware firewalls and software firewalls. A hardware firewall is a physical device that is installed between the modem and computer. A software firewall, however, is a software application that is installed onto the computer system that you wish to protect and this is usually the computer with the modem attached to it. 
Most firewalls maintain lists of rules for filtering data and of characteristics of both "safe" and "unsafe" data.  All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria. If an incoming packet of information is flagged by the filters, it is not allowed through.  The filters can be customized to restrict information and communication in a number of ways. One of the more sophisticated customization settings is the ability to ban content by certain words or phrases. This option is sometimes used by companies to prohibit their employees from accessing certain websites that would be inappropriate for the workplace. A firewall can also be used to block access to specific websites, such as popular personal email sites or even specific IP addresses.
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