Visual force page

<!--
<apex:page>  :
1. Every VF page will start and end with <apex:page>

component.
Attributes :
a. apiVersion : This will specify what type api version we are using in the VF page.
 : If you dont specify anyVersion no by default it takes lates version.
 Example : apiversion="36.0"

b. id  :
1.It is a unique string given to a component to recornize it uniquely in the  page.

c.showHeader  :
1. It is a boolean value .
2. If it is set as true salesforce header and sidebar will be displayed.
3. If it is set as false salesforce header and sidebar willnot be displayed.
4. Default value is true

d.sidebar :
1. It is a boolean value .
2. If it is set as true salesforce sidebar  will be displayed.
3. If it it set as false salesforce sidebar will be hidden.
4. Default value is true.

e. setup    :
1. It is a boolean value .
2. If it is set as true force.com setup menu will be displayed as sidebar
  component.
3. If it is set as false force.com setup menu will not be displayed.
4. Default value is false.

f. renderAs  :
1. This will render content of the page in the form PDF

2. Posssible values are pdf.

g. contentType :
1.This will specify how the content of the page should be displayed .
2. VND : view and display
Example : vnd.msword#filename.doc
 vnd.ms-excel#filename.xls

h. rendered   :
1. It is a boolean value .
2. When set as true content of the component will be displayed .
3. When set as false content of the component will be hidden
4. Default value is true

g. StandardController :
1. If you want to reffer to any one sobject in the VF page then we define
  sobject as standardController
2. Sobject can be any of the salesforce object(standard or Custom object)

i. Controller  :
1. If you want to reffer to any one the apex class in the VF page then
we define that apex class as controller.

-->

<apex:page >
  This is a first example page
</apex:page>