by Dinesh Thakur

what is lan: It actually stands for local area network. A network is a group of computers and other devices connected together so they can pass information back and forth. The local area network (LAN) is a network which is designed to operate over a small physical area such as an office, factory or a group of buildings. LANs are very widely used in a variety of applications.



 
by Dinesh Thakur

In general, a computer network composed of one or more servers, workstations, network interface cards, active and passive hub, routers, bridges, gateways, modem, software components like network operating systems, and other application software. The following components widely used for the construction of networks.



 
by Dinesh Thakur

A Distributed computing is a model of computation that is firmly related to Distributed Systems, refers to as multiple computer systems located at different places linked together over a network and use to solve higher level computation without having to use an expensive supercomputer. Distributed system is called, When collection of various computers seems a single coherent system to its client, then it is called distributed system.



 
by Dinesh Thakur

Protocol Definition: It is a digital language through which we communicate with others on the Internet. protocol meaning is that it a set of mutually accepted and implemented rules at both ends of the communications channel for the proper exchange of information. By adopting these rules, two devices can communicate with each other and can interchange information. We can't even think of using the Internet without Protocols. Each protocol is defined in different terms and different use with unique name. Message travel from sender to reciever via a medium (The medium is the physical path over which a message travels) using a protocol.



 
by Dinesh Thakur

Data link layer is the second layer in OSI reference model and lies above the physical layer. The physical layer provides only a raw bitstream service between computers. The data link layer provides data reliability and provides tools to establish, maintain, and release data link connections among the network nodes.

 
by Dinesh Thakur

The function of the network layer is to provide an end-to-end communication capability to the transport layer, which lies above it as shown in Figure. The OSI reference model specifies that the transport layer need not know the method by which the network layer performs communications.

 
by Dinesh Thakur

A computer network can be classified into different categories. Different criteria are used to classify computer networks. Following are the criteria widely used.



 
by Dinesh Thakur

The access point (abbreviated AP or WAP (for wireless access point)), is a networking hardware device, such as a wireless router, that transmits and receives data (sometimes referred to as a transceiver) and also can serve as the bridge between the WAP device and a wired LAN (Local Area Network), which facilitates connectivity between nearby wireless clients. A WAP (also known as a hotspot) acts as a central transmitter and receiver of wireless radio signals.

 
by Dinesh Thakur

Definition: Ethernet (pronounced "eether net") is a computer network technology which is used in different area networks like LAN, MAN, WAN. Ethernet connecting computers together with cable so the computers can share information. Within each main branch of the network, "Ethernet" can connect up to 1,024 personal computers and workstations.



 
by Dinesh Thakur

What is Hub: Another name of Hub is Ethernet Hub, Repeater Hub, Active Hub and Network Hub. Basically, it is a similar to switch but are not as "smart", 

Hub Definition and Meaning

hub in computer network is used for connecting multiple computers or segments of a LAN. Normally, it is used for Peer to Peer small Home Network. LAN Hub receive data packets (frames) through one port and broadcasts them through all other ports, so that all other computers or other network devices can see all packets.



 
by Dinesh Thakur

Digital Equipment Corporation (DEC) has given support to network connectivity for networks of its own and networks of other vendors also. DEC has its own architecture known as Digital Network Architecture (DNA) the product that implements the architecture is known as DEC net. The DNA was developed during 1974, to provide communication facility between various DEC systems.

 
by Dinesh Thakur

The Systems Network Architecture (SNA) from IBM uses a 7 layer architecture similar to the OSI model.

 
by Dinesh Thakur

Definition:  General Packet Radio Service is a packet-based wireless communication service. It promises data rate up to 114 kbps. It is a standard technology which extends the Global system. It abbreviated as GPRS. It is designed to replace the current circuit-switched services.

General Packet Radio Service is a non-voice and high-speed technology which is useful for the GSM networks. We make use of GPRS so that we can enable connections which depend on the internet protocol. As we know, IP supports a wide variety of applications. We can send and receive the compressed data and large volume data over the mobile network by using GPRS as the packet switching system used. So, before sending the data, it breaks the whole data into packets and then shifts them through the network. Now the data again assembled at the recipient side.



 
by Dinesh Thakur

Cluster computing or High-Performance computing frameworks is a form of computing in which bunch of computers (often called nodes) that are connected through a LAN (local area network) so that, they behave like a single machine. A computer cluster help to solve complex operations more efficiently with much faster processing speed, better data integrity than a single computer and they only used for mission-critical applications.



 
by Dinesh Thakur

In order to provide computer to computer communication via Internet, we need a global addressing scheme. Such an addressing is provided by Internet Protocol (IP) at the network layer.
It is a 32-bit address This is called an IP address or logical address. Which is made up of the network ID, plus a unique host ID. This address is typically represented with the decimal value of each octet separated by a period (for example, 192.168.7.27).   Every Host and router on the internet has an IP Address. This IP address is unique and no two devices on the Internet can have the same address at the same time.



 
by Dinesh Thakur

What is http: HTTP full form HyperText Transfer Protocol used mainly to access data on the World Wide Web. HTTP is a Server and Client communication Protocol, which is primarily set of rules for formating and transferring webpage data (text, images, video and Multimedia files) over the world wide web. This is the Protocol used to create communication between Web Servers and Web Users. HTTP is an application layer Protocol that works on the top of the TCP/IP suite of Protocols.

 
by Dinesh Thakur

VPN (Virtual Private Network) Definition: VPN meaning that it is a private point-to-point connection between two machines or networks over a shared or public network such as the internet. A Virtual Private Network is a combination of software and hardware. VPN (Virtual Private Network) technology, can be use in organization to extend its safe encrypted connection over less secure internet to connect remote users, branch offices, and partner private, internal network. VPN turn the Internet into a simulated private WAN.



 
by Dinesh Thakur

The INSERT statement is used to add new row to a table. To insert new row(s) into a table, the table must be in your own schema or you must have INSERT privilege on the table. Only one row is inserted at a time with this syntax. You can insert literal values (26.5, 'DINESH), expres­sions containing operators and functions, null values etc. only.

 
by Dinesh Thakur

There are times when you want to prevent inheritance. Perhaps there is no need the extensibility for various reasons. If you know this for sure, there are advantages to declaring the final keyword precisely that.

Java has a special keyword called final that can use for creating final methods, final classes, and final variables. The final modifier is void, which simply means that no value is returned.The final modifier indicates that the value of this member cannot change. We get a compile-time error if our program tries to change its contents. Each of these is explained in more detail next.

 
by Dinesh Thakur

Java is a robust, general-purpose, high-level programming language and a powerful software platform. It is also object-oriented, distributed, portable and multi-threaded. Java follows the 'Write - once - run - anywhere' approach. All Java programs must run on the Java platform that has two components, the Java Virtual Machine (JVM) and the Java Application Programming Interface (API).

 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.