Answer:- • NOS stands for Network Operating System. It is specialized software which is used to provide network connectivity to a computer to make communication possible with other computers and connected devices. • NOS is the software which allows the device to communicate, share files with other devices. • The first network operating system was Novel NetWare released in 1983. Some other examples of NOS are Windows 2000, Windows XP, Linux, etc.

Answer:- Networks can be divided on the basis of area of distribution. For example: • PAN (Personal Area Network): Its range limit is up to 10 meters. It is created for personal use. Generally, personal devices are connected to this network. For example computers, telephones, fax, printers, etc. • LAN (Local Area Network): It is used for a small geographical location like office, hospital, school, etc. • HAN (House Area Network): It is actually a LAN that is used within a house and used to connect homely devices like personal computers, phones, printers, etc. • CAN (Campus Area Network): It is a connection of devices within a campus area which links to other departments of the organization within the same campus. • MAN (Metropolitan Area Network): It is used to connect the devices which span to large cities like metropolitan cities over a wide geographical area. • WAN (Wide Area Network): It is used over a wide geographical location that may range to connect cities and countries. • GAN (Global Area Network): It uses satellites to connect devices over global are.

Answer:- POP3 stands for Post Office Protocol version3. POP is responsible for accessing the mail service on a client machine. POP3 works on two models such as Delete mode and Keep mode.

Answer:- MAC stands for Media Access Control. It is the address of the device at the Media Access Control Layer of Network Architecture. It is a unique address means no two devices can have same MAC addresses.

Answer:- IP address is a unique 32 bit software address of a computer in a network system.

Answer:- There are three ranges of IP addresses that have been reserved for IP addresses. They are not valid for use on the internet. If you want to access internet on these private IPs, you must have to use proxy server or NAT server.

Answer:- A public IP address is an address taken by the Internet Service Provider which facilitates you to communication on the internet.

Answer:- APIPA is an acronym stands for Automatic Private IP Addressing. This feature is generally found in Microsoft operating system.

Answer:- • ADS stands for Active Directory Structure. • ADS is a microsoft technology used to manage the computers and other devices. • ADS allows the network administrators to manage the domains, users and objects within the network. • ADS consists of three main tiers: o Domain: Users that use the same database will be grouped into a single domain. o Tree: Multiple domains can be grouped into a single tree. o Forest: Multiple trees can be grouped into a single forest.

Answer:- RAID is a method to provide Fault Tolerance by using multiple Hard Disc Drives.

Answer:- Anonymous FTP is used to grant users access to files in public servers. Users which are allowed access to data in these servers do not need to identify themselves, but instead log in as an anonymous guest.

Answer:- A protocol is a set of rules which is used to govern all the aspects of information communication.

Answer:- The main elements of a protocol are: • Syntax: It specifies the structure or format of the data. It also specifies the order in which they are presented. • Semantics: It specifies the meaning of each section of bits. • Timing: Timing specifies two characteristics: When data should be sent and how fast it can be sent.

Answer:- There are two types of client/server programs. First is directly used by the users and the second supports application programs. The Domain Name System is the second type supporting program that is used by other programs such as to find the IP address of an e-mail recipient.