Network Interface Controller/Card (NIC)

NIC or network interface card or network adapter, LAN adapter is an important  hardware requirement for connectivity . Actually this interface  card provides us the 'gateway' through which data from one computer A can be transfered to another computer B. Its somewhat the  same as normal gate that we use in daily life to enter and exit.
A NIC technically is network adapter hardware in the form factor of an add-in card such as a PCI or PCMCIA card. Its actually a stick( looking somewhat like ram) and is mostly having an RJ45 connector at their one end.( u can see it at the back of ur laptop or PC..its where ur Ethernet wire is attached). Here is an image of what NIC looks like:

NIC is OSI layer 2 device (DATA LINK LAYER U can see this for more osi blog) . its consist of factory fitted 48bit address similar to that of ip address, here its called the MAC address or the Media Access Control address which is in .human-friendly form, is represented in  six groups of two hexadecimal digits, separated by hyphens (-)  or  colons (:), in transmission order.
For example ,consider the following

• 01-23-45-67-89-ab

•  01:23:45:67:89:ab

•  0001.4202.8360

the last one is not used much now days.


One important point to be noted about the MAC address is that " each system has a unique MAC address in an LAN ,but not universally as IP address".
there are several variety of NIC avaialable these days in market.The biggest variation between cards is depending upon their connective medium and speed capabilities. few of them are as follow:-

1. 10/100 Ethernet--they are able of speeds up to 10 or 100 megabits per second, not to be confused with megabytes per second(Even i did the same mistake in my final Sems).
2. Gigabit Ethernet--Gigabit Ethernet NICs give network transfer speeds of up to one Gigabit per second.
3. Wireless NIC--Wireless NICs give similar networking capabilities as wired counterparts. Wireless networking permits for freedom in PC topology and installation

NIC is just another peripheral devices attached to a system and  transfers data similarily. its might use DMA or Polling or INTERRUPT .
So in the next blog i will be talking OSI MODEL and its usage ,till then BEST OF LUCK

keep looking ....