Basic Terms Used in Computer Network

1: IP Address
An Internet Protocol address (IP Address) is an unique identification number assigned to each devices connected in a network that uses Internet protocol for communication. The typical IP address looks like 
216.27.67.137
IP address are expressed in decimal as above which is easier for us to remember, but computers communicate in binary. So same IP address looks like
11011000.00011011.00111101.10001001

IP address has four sets of number separated by a period ( . ), These sets are Called Octets. IP address perform mainly two functions. One is identification of Network and Identification of particular host in that network.

2. MAC address 
Media Access Control (MAC) address also known as hardware or physical address is unique number associated with a network adapter (NIC). It is used to uniquely identify each device (node) of a network. MAC address is usually assigned by the manufacturer of a network interface card (NIC) and are stored in its ROM. All NIC developed contains unique MAC address. It is a 12 digit hexadecimal number (48 bit in length) and are Witten in following formats.
MM:MM:MM:SS:SS:SS or MM-MM-MM-SS-SS-SS

The first half of the address contains ID number of the adapter regulated by an Internet standards body and other half represent the number assigned by the manufacturer.For example: 00:A0:C9:14:C8:29
The prefix 00A0C9 indicates manufactures Intel Corporation and 14C829 indicates a particular host.

3. Intranet: An intranet is a private network that uses internet protocols, to securely share part of an organization's information between its employees. An intranet is a Local Area Network or Wide Area Network that uses TCP/IP protocol but, belongs to a corporation, school, or organization. The intranet is accessible only to the organization's workers. If the intranet is connected the Internet, then it is secured by a firewall to prevent unauthorized users from gaining access to it. Advantages of an Intranet

1. Workforce productivity: Employees can easily access and share information in-between their workgroups which enhances productivity

2. Time: With intranets, organizations can make more information available to employees in any time.

3. Communication: Intranets can serve as powerful tools for communication within an organization.

4. Extranet: An extranet is a private intranet that can be accessed by outside users over the secure channel. To gain entrance to the extranet's resource, an external user must log on to the networks by providing a valid user ID and password. The extranet is a combination of the public Internet and the closed intranet. 

Difference between Internet and Intranet?