network computer

The next stage that we know about the CPU and Memory, Virus computer now we begin to re-discuss the Computer Network.

Three centuries before now, each marked with a different dominance. The 18th century was dominated by the development of mechanical systems that accompanied the industrial revolution. The 19th century is the era of the steam engine. The 20th century, the technology of radio, tv and computers play a role for the collection, processing and distribution of media information. The 21st century-era current or information, which the global computer network technology that is able to reach all areas of the world, the development of systems and technologies used, the dissemination of information through the internet, launching communication satellites and wireless communications devices / phones marked the beginning of the century millenium.
Since his community his Internet and Windows95 operating system marketed by Microsoft Inc., Connect multiple computers both personal computers (PCs) and servers with a network of this type of LAN (Local Area Network) to the WAN (Wide Area Network) becomes a thing simple and plain. Similarly, the concept of "downsizing" or "lightsizing" aimed at pressing budget (budget efficiency), particularly computer equipment, the need for a computer network is one thing that can not be inevitable.

    Definition of Computer Networks
The computer network is the "interconnection" between two or more autonomous computers, connected to the transmission media cable or wireless (wireless).
Autonomous is when a computer does not take control of other computers with full access, so as to make the other computer, restart, shutdows, file loss or system damage. In another definition of networking is described as autonomous independent network with its own management system (have admin itself), has a network topology, hardware and software themselves, and connect with other autonomous network. (The Internet is an example of a collection of autonomous network is very large.)
Two computers can be said to be connected if they exchange data / information, sharing resources owned, such as files, printers, storage media (hard disk, floppy disk, cd-rom, flash disks, etc.). Data in the form of text, audio and video, moving through wires or wireless media (wireless) to enable the computer users in the computer network to exchange files / data, print on the same printer and using hardware / software connected together in a network
Each computer, printer or peripherals connected to a network is called a "node". A computer network consists of at least two or more computers, the computer can amount to tens of thousands or even millions of nodes that are connected to each other. Known computer systems in the network connections between nodes (computers), namely:

    Peer topeer
Peer meaning colleagues. Peer-to-peer network is a computer network consisting of several computers, connected directly with a crossover cable or a wireless or even the intermediate hub / switch.
Computers on peer to peer networks are usually few in number with 1-2 printers. For specific use, such as computer labs, research and a few other things, then the model is peer to peer connections could be developed for more than 10 to 100 computers.
Peer to peer is a model in which each PC can use the resource on another PC or give resourcenya to use another PC, No one acts as server that manages communication systems and computer resource usage dijaringan contained, in other words, any computer can function as a client and servers in the same period.
For example, there are several computers in one department, given the name of the group in accordance with the departments concerned. Each computer assigned an IP address from the IP of the same class to be able to share with each other to exchange data or resource owned by each computer, such as printers, cdrom, and other files.
Figure Peer to peer

    Client - Server
Client Server is a network model that uses a single or multiple computers as a server that provides the resource to another computer (client) in the network, the server will manage resource access mechanisms that may be used, as well as the communication mechanism between the nodes in the network.
In addition to the local network, this system can also be applied to internet technology. Where there is a computer unit) functions as a server which only provides services to other computers, and a client who also just request a service from a server. Access is done transparently from the client by first logging into the destination server.
Figure Client Server
Client can only use the resources provided by a server in accordance with the authority granted by the administrator. Applications that run on the client side, it could be a resource available on the server. but can only be run after connecting to the server. On the implementation of software that are installed splikasi client side is different from that used on the server.
Client-server type of service include:

    File Server: provide file management functions.
     Print Server: Server pencetakan.Database of service functions: the functional processes of the database running on this machine and the other station can request the service
     DIP (Document Information Processing): providing service function storage, management and retrieval of data
Pros Network Pear To Pear

    Implementation is cheap and easy
    It does not require special software network administration
     Does not require network administrators
Lack Network Pear To Pear

     Networks can not be too big (can not enlarge the network.
    Low level of security.
    No one manage the network.
    Computer users should be trained to secure computer networks respectively.
    The more machines disharing, will affect computer performance
v Client Sever Kelebhan

    Supports better network security
    Ease of administration when networks increase in size
     Centralized network management
     All data can be stored and backed up centrally in one location

      Disadvantages Client Sever

    Need a professional network administrator
     It took a good device to use as a computer server
     Need software tools to simplify network management operations.
     The budget for a major network management.
     If the server is down, all of the data and can not be accessed in server resource