In Sharepoint, we can create any number of web applications. Each Web Application has to contain minimum one Site Collection(SPSite) and each Site Collection has to contain minimum of one Site(SPWeb). Each Site contains any number of Sub Sites(SPWeb).

Here we discuss about creating a new Web Application in Sharepoint from Central Administration. To create a Web Application Open Central Administration, Click on Application Management tab and Select Manage web applications as shown below.

Now Click on New tab on Manage web application screen which is located on top left of the screen as shown below.
 

After selecting the New option from Manage web applications, you will get the screen as shown below with different inputs. We discuss about each input here.
 

Authentication Section

Here you can select any one of Authentication from Claims Based Authentication and Classic Mode Authentication. By default Classic Mod Authentication is selected.

IIS Web Site Section 

In Sharepoint if we create any Web Application, it creates the new web site in IIS. From the options select Create a new IIS web site and provide the web site name; by default it is Sharepoint  – 34378(here 34378 is the port number).  Enter the port number; by default it takes any random port from available ports.

Provide the Host Header; by default it is empty. Enter path where you want to save particular web application content; by default it creates the folder with port number and save in the C:\inetpub\wwwroot\wss\VirtualDirectories directory. Here the value of the Path is C:\inetpub\wwwroot\wss\VirtualDirectories\34378.

Security Configuration Section

Select Authentication provider; by default system will select NTLM option. Select option for Allow Anonymous option; by default its value is No. Select Use Secure Socket Layer(SSL) option; by default system will select as No.

Public URL

Enter value Public URL option. Please enter available URL only for Public URL field.

Application Pool Section

By default system will select the Create New Application Pool Option. Enter the Application Pool Name; by default system will provide the name as Sharepoint – 34378(34378 is port number). Select a Security account for this application pool; by default system will select Configurable option.  Enter the User Name( for example MYDOMAIN\Administrator).

Database Name and Authentication

Enter the database server name(for example SP2010\SQLExpress), Enter the database name; by default system will provide database name like WSS_Content_5f5ecf40e555472caa6c586ac1c62cb8. Select Authentication for particular database; by default system will select Windows authentication mode.

For Failover Server field, you can choose to associate a database with a specific failover server that is used in conjunction with SQL Server database mirroring.

For Search service is provided by SharePoint Server Search.

After entering the all required fields Click Ok and Sharepoint will take some time to process the request as shown below.

After Web Application created it displays the confirmation window as shown below, Click on Create Site Collection link.

Once you Click on Create Site Collection, it will open new window to create Site Collection for particular Web Application as shown below.

Enter the Title, Description for Site Collection. Select Team Site from Collaboration under Template Section. Provide the User name for Primary Site Collection Administrator and Secondary Site Collection Administrator(for example MYDOMAIN\Administrator). Click on OK button to create the Site Collection for our Web Application.

To check whether Web Application is Created Or Not, Go to Central Administration => Application Management and Select Manage Web Applications. There you can find Web Application just now you created as shown below.

Open the Web Application by entering the URL http://sp2010:34378/ in browser and output is as shown below.