Networking

Computer Network-
 It is an interconnected collection of autonomous computers or system of computers capable of sharing resources and controlling services.
 Interconnecting a set of computers with each other using transmission media is called a network.
The rules governing computer communication are called protocols.
Networking allows us to do the following;:-
1)Exchanging information
2)Sharing hardware resouces
3)Preserving information
4)Protecting information

Network installations is major factor in networking, they are of three types:-
1)Centralized installation
2)Distibuted installation
3)Collaborative installation

Types of networks:-
1)LAN -Local Area Network
2)MAN-Metropolitan Area Network
3)WAN- Wide Area Network

Network Topologies:-
1)Star topology
2)Bus topology
3)Ring topology
4)Mesh topology

Network Configurations:-
1)Network configuration means the method of operating a network by deciding the node authorities.
There are two basic configurations:-
1)Client-Server configuration
2)Peer to Peer configuration

WWW:-
It is World Wide Web one of the internet application.In the internet ,different types of  computers are connected to each other.These computers may have different operating systems.
When the data is to be transformed from one computer to other computer, and the operating system of both the computers are different, then both operating system should understand the data format, which is to be transferred.The www provides an interactive document and the software to access the data on any computer.The document has pages,which can combine text, picture, form, sound, animation and hyperlinks.

ASP.NET

ASP.NET : -    

ASP -

The full form of it is :A for Active ,S for Server ,P for Pages.

Active Server Pages (ASP), also known as Classic ASP, was introduced in 1998 as Microsoft's first server side scripting engine.
ASP is a technology that enables scripts in web pages to be executed by an Internet server.
ASP pages have the file extension .asp, and are normally written in VBScript.

ASP.NET - ASP.NET pages are compiled.
ASP.NET has better language support, a large set of user controls, XML-based components, and integrated user authentication.
ASP.NET pages have the extension .aspx, and are normally written in VB (Visual Basic) or C# (C sharp).
User controls in ASP.NET can be written in different languages, including C++ and Java.
When a browser requests an ASP.NET file, the ASP.NET engine reads the file, compiles and executes the scripts in the file, and returns the result to the browser as plain HTML.

Why .NET ? OR Advantages of .NET -
1)It is complete technology .Console based ,web based ,client based ,window based applications are in it.
2)It is Language Independent . No need to learn other language.In above 50 + language it can be used.
3) It is Platform Independent .Partially platform independent with editor text which support .NET the Microsoft operating system runs .NET on all of its version .In Linux with MonoExe we can run in it also .Support on windows 7,XP,etc.
4) Automatic Memory Management .By GArbage collector it automatically makes memory management by its algorithm (Disposes,Recall,Algo's)
5)Security
6)It support Interoperability. If project written in VS-6 it can access easi;ly in VS-8.

Note:-
In Notepad .cs can run visual Studio is rich provides help in Dot providing.

.NET Framework:-
Two main components of .NET framework are
1)Frameclass Libraries/Base class libraries
2)Common Language Run-time (Heart  of .NET framework)-Here all .NET application are executed .   

ADO.NET -Active X Data Object .NET make the code simple.
It is divided into two parts -
1)Connected architecture -It has (example:Desktop required all time connection)
a) Connection object
b) Command object(place where we write query)
c) Data Reader(forward only,read only)
d) Data Adapter
2)Disconnected architecture - It has(example: Laptop requires charging)
a)Data Sets-(Insert /update/delete)
     i)Data table
     ii) Data Row
     iii) Data Column
b)Data Relation


Methods of Command objects:-
1)Sql Data Reader dr =cmd.ExecuteReader();
return type is Sql data Reader dr
When there is single query for multiple results use this blindly for select.query.
2)int i =cmd.Execute non.Query();
use this method when there is data Data manipulate query for insert ,update,delete.
3)object obj = cmd.ExecuteScalar();
use this method for query returning single value .
These are used only in Connected architecture and not in disconnected.

Interface-
1)variables ,constructors are not declared .
2)only methods are declared.
3)they are public access by default so no need to write access.
4)There is contract in class and interface 3methods of interface are 100% compulsory.

Collections:-
In Collection we have
1)Sequential collection .
2)Dictionary collection.
3)Specialized collection.
4)Generic collection.