What is Coaxial cable? types of coaxial cable?

Coaxial Cable

A type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire. The shield minimizes electrical and radio frequency interference.
Coaxial cabling is the primary type of cabling used by the cable television industry and is also widely used for computer networks, such as Ethernet. Although more expensive than standard telephone wire, it is much less susceptible to interference and can carry much more data.

What isTwisted-pair cable? What is STP & UTP? Difference between UTP & STP?

Twisted-pair cable

Twisted-pair cable is the most common type of cabling you can see in today's Local Area Networks (LAN) networks.  A pair of wires forms a circuit that can transmit data. The pairs are twisted to provide protection against Crosstalk. It is the undesired signal noise generated by the Electro-Magnetic fields of the adjacent wires. When a wire is carrying a current, the current creates a magnetic  field around the wire.  This field can interfere with signals on nearby wires.  To eliminate this, pairs of wires carry signals in opposite directions, so that the two magnetic fields also occur in opposite directions and cancel each other out. This process is known as cancellation.

Two Types of Twisted Pairs are Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP).

Unshielded twisted-pair (UTP) consists of four pairs of thin, copper wires covered in color-coded plastic insulation that are twisted together. The wire pairs are then covered with a plastic outer jacket.

UTP cables are of small diameter and it doesn’t need grounding. Since there is no shielding for UTP cabling, it relies only on the cancellation to avoid noise. 

Colors used for Twisted Pair wires are Orange, Orange-White, Blue, Blue-White, Green, Green-White, Brown and Brown-White. 

What is Wired or Guided Media or Bound Transmission Media.

Wired or Guided Media or Bound Transmission Media:

Bound transmission media are the links that are substantial or have physical presence and are restricted by the physical geography. Mainstream bound transmission media being used are

1. Turned(twisted) pair link, 
2. Co-axial link and 
3. Fiber optical link. 

Each of them has its own particular qualities like transmission rate, impact of clamor, physical appearance, cost and so forth.

What is Remote or Unguided Media or Unbound Transmission Media.

Remote or Unguided Media or Unbound Transmission Media:

Unbound transmission media are the methods for transmitting information without utilizing any links. These media are not limited by physical geography. This kind of transmission is called Wireless communication. These days remote(wireless) communication is become populer. Remote LANs are being introduced in office and school grounds. This transmission utilizes Microwave, Radio wave, Infra red are some of prominent unbound transmission media.

The data transmission capabilities of various Medias vary differently depending upon the various factors. These factors are:

1. Bandwidth. 

It refers to the data transferring capacity of a channel or link. maximum bandwidth communication links support maximum data rates.

2. Radiation. 

It refers to the outflow of signal from the channel due to unwanted electrical appearance of the channel.

3. Noise Absorption. 

It refers to the susceptibility of the media to external electrical noise that can cause distortion of data signal.

4. Attenuation. 

It refers to loss of energy as signal propagates outwards. The amount of energy lost depends on frequency. Radiations and physical characteristics of media contribute to attenuation.

What is Transmission Media? types of Transmission Media.

Transmission Media

The transmission media of a computer network describes the material substances that carry energy waves, which include the data being transferred.

The two main categories are wired, or guided, which uses physical cables, and wireless, or unguided, which uses electromagnetic waves that can travel through a medium, such as air.

Wireless signals do not require a physical medium, such as cables.

Transmission media is broadly classified into two groups.

1. Wired or Guided Media or Bound Transmission Media.

2. Remote or Unguided Media or Unbound Transmission Media.

Who Owns the Internet?

Who Owns the Internet?

No one actually owns the Internet, and no single person or organization 

controls the Internet in its entirety.

There are many organizations, corporations, governments, schools, private 

citizens and service providers that all own pieces of the infrastructure, 

but there is no one body that owns it all.

There are, however, organizations that oversee and standardize what happens 

on the Internet and assign IP addresses and domain names, such as the National 

Science Foundation, the Internet Engineering Task Force, ICANN,  InterNIC  and 

the Internet Architecture Board.

what is network interface card (NIC)? why it use?

NIC network interface card 

Short for Network Interface Card, the NIC is also referred to as an Ethernet card and network adapter.
(NIC) is a circuit board or card that is installed in a computer so that it can be connected to a network. 

A network interface card provides the PC with a committed, full-time association with a network. PCs and workstations on a Local area network (LAN) ordinarily contain a network interface card particularly intended for the LAN transmission technology.